Prevalence of Substance Misuse, with a Focus on Alcohol Misuse

Alcohol misuse is a major issue, particularly in the UK, where it is among the highest rates in Europe. Men are more likely to experience both alcohol dependence and binge drinking than women. Specifically, 6% of men and 2% of women experience alcohol dependence, while 21% of men and 9% of women engage in binge drinking. It is worth noting that this figure contradicts the findings from the NPMS in 2000.

ADHD, depression, learning disabilities, substance misuse, psychosis, and autism are frequently observed alongside conduct disorders.

Disruptive Behaviour of Dissocial Disorders

Conduct disorders are the most common reason for referral of young children to mental health services. These disorders are characterized by a repetitive and persistent pattern of antisocial, aggressive, of defiant conduct that goes beyond ordinary childish mischief of adolescent rebelliousness. Oppositional defiant disorder (ODD) shares some negative attributes but in a more limited fashion.

ICD-11 terms the disorder as ‘Conduct-dissocial disorder’, while DSM-5 recognizes three separate conditions related to emotional/behavioral problems seen in younger people: conduct disorder, oppositional defiant disorder, and intermittent explosive disorder. Conduct disorder is about poorly controlled behavior, intermittent explosive disorder is about poorly controlled emotions, and ODD is in between. Conduct disorders are further divided into childhood onset (before 10 years) and adolescent onset (10 years of older).

The behavior pattern of conduct disorders must be persistent and recurrent, including multiple incidents of aggression towards people of animals, destruction of property, deceitfulness of theft, and serious violations of rules. The pattern of behavior must result in significant impairment in personal, family, social, educational, occupational, of other important areas of functioning.

Oppositional defiant disorder represents a less severe form of conduct disorder, where there is an absence of more severe dissocial of aggressive acts. The behavior pattern of ODD includes persistent difficulty getting along with others, provocative, spiteful, of vindictive behavior, and extreme irritability of anger.

The prevalence of conduct disorders increases throughout childhood and is more common in boys than girls. The most frequent comorbid problem seen with conduct disorder is hyperactivity. The conversion rate from childhood conduct disorder to adult antisocial personality disorder varies from 40 to 70% depending on the study.

NICE recommends group parent-based training programs of parent and child training programs for children with complex needs for ages 3-11, child-focused programs for ages 9-14, and multimodal interventions with a family focus for ages 11-17. Medication is not recommended in routine practice, but risperidone can be used where other approaches fail and they are seriously aggressive.

After a 12 week trial of an SSRI with no improvement, NICE recommends switching to a different type of antidepressant such as imipramine of clomipramine.

Understanding Panic Disorder: Key Facts, Diagnosis, and Treatment Recommendations

Panic disorder is a mental health condition characterized by recurrent unexpected panic attacks, which are sudden surges of intense fear of discomfort that reach a peak within minutes. Females are more commonly affected than males, and the disorder typically onsets during the early 20s. Panic attacks are followed by persistent concern of worry about their recurrence of negative significance, of behaviors intended to avoid their recurrence. The symptoms result in significant impairment in personal, family, social, educational, occupational, of other important areas of functioning.

To diagnose panic disorder, the individual must experience recurrent panic attacks that are not restricted to particular stimuli of situations and are unexpected. The panic attacks are followed by persistent concern of worry about their recurrence of negative significance, of behaviors intended to avoid their recurrence. The symptoms are not a manifestation of another medical condition of substance use, and they result in significant impairment in functioning.

Panic disorder is differentiated from normal fear reactions by the frequent recurrence of panic attacks, persistent worry of concern about the panic attacks of their meaning, and associated significant impairment in functioning. Treatment recommendations vary based on the severity of the disorder, with mild to moderate cases recommended for individual self-help and moderate to severe cases recommended for cognitive-behavioral therapy of antidepressant medication. The classes of antidepressants that have an evidence base for effectiveness are SSRIs, SNRIs, and TCAs. Benzodiazepines are not recommended for the treatment of panic disorder due to their association with a less favorable long-term outcome. Sedating antihistamines of antipsychotics should also not be prescribed for the treatment of panic disorder.

The CAMDEX assessment is not effective in detecting dementia in adults with learning disabilities, whose developmental ages are typically between 2 and 10 years. However, the Dementia Questionnaire for People with Learning Disabilities (DLD) is a useful tool for early detection of dementia in this population. For individuals with Down’s syndrome, an adapted version of the CAMDEX called the CAMDEX-DS can be utilized.

Assessment of Dementia in Down’s Syndrome

Individuals with Down’s syndrome are at a higher risk of developing Alzheimer’s disease. However, the commonly used MMSE test is not effective in assisting diagnosis in this population. Instead, two alternative tests are recommended: the Dementia Questionnaire for people with Learning Disabilities (DLD), previously known as the Dementia Questionnaire for Persons with Mental Retardation (DMR), and the Dementia Scale for Down Syndrome (DSDS). These tests are specifically designed to assess cognitive decline in individuals with Down’s syndrome and can aid in the early detection and management of dementia in this population.

of the symptoms mentioned, irritability is the only one that is associated with PTSD.

Stress disorders, such as Post Traumatic Stress Disorder (PTSD), are emotional reactions to traumatic events. The diagnosis of PTSD requires exposure to an extremely threatening of horrific event, followed by the development of a characteristic syndrome lasting for at least several weeks, consisting of re-experiencing the traumatic event, deliberate avoidance of reminders likely to produce re-experiencing, and persistent perceptions of heightened current threat. Additional clinical features may include general dysphoria, dissociative symptoms, somatic complaints, suicidal ideation and behaviour, social withdrawal, excessive alcohol of drug use, anxiety symptoms, and obsessions of compulsions. The emotional experience of individuals with PTSD commonly includes anger, shame, sadness, humiliation, of guilt. The onset of PTSD symptoms can occur at any time during the lifespan following exposure to a traumatic event, and the symptoms and course of PTSD can vary significantly over time and individuals. Key differentials include acute stress reaction, adjustment disorder, and complex PTSD. Management of PTSD includes trauma-focused cognitive behavioral therapy (CBT), eye movement desensitization and reprocessing (EMDR), and supported trauma-focused computerized CBT interventions. Drug treatments, including benzodiazepines, are not recommended for the prevention of treatment of PTSD in adults, but venlafaxine of a selective serotonin reuptake inhibitor (SSRI) may be considered for adults with a diagnosis of PTSD if the person has a preference for drug treatment. Antipsychotics such as risperidone may be considered in addition if disabling symptoms and behaviors are present and have not responded to other treatments. Psychological debriefing is not recommended for the prevention of treatment of PTSD. For children and young people, individual trauma-focused CBT interventions of EMDR may be considered, but drug treatments are not recommended.

An ecological fallacy is a potential error that can occur when generalizing relationships observed among groups to individuals. This is a concern when conducting analyses of ecological studies.

Types of Primary Research Studies and Their Advantages and Disadvantages

Primary research studies can be categorized into six types based on the research question they aim to address. The best type of study for each question type is listed in the table below. There are two main types of study design: experimental and observational. Experimental studies involve an intervention, while observational studies do not. The advantages and disadvantages of each study type are summarized in the table below.

Type of Question Best Type of Study

Therapy Randomized controlled trial (RCT), cohort, case control, case series
Diagnosis Cohort studies with comparison to gold standard test
Prognosis Cohort studies, case control, case series
Etiology/Harm RCT, cohort studies, case control, case series
Prevention RCT, cohort studies, case control, case series
Cost Economic analysis

Study Type Advantages Disadvantages

Randomized Controlled Trial – Unbiased distribution of confounders – Blinding more likely – Randomization facilitates statistical analysis – Expensive – Time-consuming – Volunteer bias – Ethically problematic at times
Cohort Study – Ethically safe – Subjects can be matched – Can establish timing and directionality of events – Eligibility criteria and outcome assessments can be standardized – Administratively easier and cheaper than RCT – Controls may be difficult to identify – Exposure may be linked to a hidden confounder – Blinding is difficult – Randomization not present – For rare disease, large sample sizes of long follow-up necessary
Case-Control Study – Quick and cheap – Only feasible method for very rare disorders of those with long lag between exposure and outcome – Fewer subjects needed than cross-sectional studies – Reliance on recall of records to determine exposure status – Confounders – Selection of control groups is difficult – Potential bias: recall, selection
Cross-Sectional Survey – Cheap and simple – Ethically safe – Establishes association at most, not causality – Recall bias susceptibility – Confounders may be unequally distributed – Neyman bias – Group sizes may be unequal
Ecological Study – Cheap and simple – Ethically safe – Ecological fallacy (when relationships which exist for groups are assumed to also be true for individuals)

In conclusion, the choice of study type depends on the research question being addressed. Each study type has its own advantages and disadvantages, and researchers should carefully consider these when designing their studies.

Personality Disorder (Borderline)

History and Terminology

The term borderline personality disorder originated from early 20th-century theories that the disorder was on the border between neurosis and psychosis. The term borderline was coined by Adolph Stern in 1938. Subsequent attempts to define the condition include Otto Kernberg’s borderline personality organization, which identified key elements such as ego weakness, primitive defense mechanisms, identity diffusion, and unstable reality testing.

Features

The DSM-5 and ICD-11 both define borderline personality disorder as a pervasive pattern of instability in interpersonal relationships, self-image, and affects, and marked impulsivity. Symptoms include efforts to avoid abandonment, unstable relationships, impulsivity, suicidal behavior, affective instability, chronic feelings of emptiness, difficulty controlling temper, and transient dissociative symptoms.

Abuse

Childhood abuse and neglect are extremely common among borderline patients, with up to 87% having suffered some form of trauma. The effect of abuse seems to depend on the stage of psychological development at which it takes place.

comorbidity

Borderline PD patients are more likely to receive a diagnosis of major depressive disorder, bipolar disorder, panic disorder, PTSD, OCD, eating disorders, and somatoform disorders.

Psychological Therapy

Dialectical Behavioral Therapy (DBT), Mentalization-Based Treatment (MBT), Schema-Focused Therapy (SFT), and Transference-Focused Psychotherapy (TFP) are the main psychological treatments for BPD. DBT is the most well-known and widely available, while MBT focuses on improving mentalization, SFT generates structural changes to a patient’s personality, and TFP examines dysfunctional interpersonal dynamics that emerge in interactions with the therapist in the transference.

NICE Guidelines

The NICE guidelines on BPD offer very little recommendations. They do not recommend medication for treatment of the core symptoms. Regarding psychological therapies, they make reference to DBT and MBT being effective but add that the evidence base is too small to draw firm conclusions. They do specifically say Do not use brief psychotherapeutic interventions (of less than 3 months’ duration) specifically for borderline personality disorder of for the individual symptoms of the disorder.

Factors that Increase the Risk of Recurrent Depression

Depression is a disorder that often recurs. Research shows that 50-85% of individuals who experience a single episode of depression will have a second episode, and of those, 80-90% will have a third episode (Forshall, 1999). Due to the high likelihood of recurrence, NICE recommends that individuals who have had two of more episodes of depression in the recent past should continue taking antidepressants for at least two years.

Several factors increase the risk of recurrent depression, including a family history of depression, recurrent dysthymia, concurrent non-affective psychiatric illness, female gender, long episode duration, chronic medical illness, and lack of a confiding relationship. It is important for individuals with a history of depression to be aware of these risk factors and to work with their healthcare provider to develop a plan for preventing future episodes.

Individuals diagnosed with schizophrenia have a higher prevalence of smoking compared to the general population, with earlier onset and greater difficulty in quitting. This leads to increased cardiovascular comorbidity. Furthermore, smoking can induce CYP450 enzyme systems, which can interfere with the effectiveness of medications like clozapine.

According to Greenhalgh (1997), when making decisions about clinical interventions, the standard notation for the relative weight carried by different types of primary studies is arranged in a hierarchy of evidence. Randomised control trials with non-definitive results are ranked third in this hierarchy, carrying stronger relative weight than cohort studies, case-control studies, cross-sectional surveys, and case reports. The top two positions are occupied by systematic reviews/meta-analyses and RCTs with definitive results, respectively.

Bipolar Disorder Diagnosis

Bipolar and related disorders are mood disorders characterized by manic, mixed, of hypomanic episodes alternating with depressive episodes. The lifetime risk of suicide in individuals with bipolar disorder is estimated to be at least 15 times that of the general population. Under the ICD-11, there are three subtypes of bipolar disorder: Bipolar I, Bipolar II, and Cyclothymic disorder.

Bipolar I disorder is diagnosed when an individual has a history of at least one manic of mixed episode. The typical course of the disorder is characterized by recurrent depressive and manic of mixed episodes. Onset of the first mood episode most often occurs during the late teen years, but onset of bipolar type I can occur at any time through the life cycle. The lifetime prevalence of bipolar I disorder is estimated to be around 2.1%.

Bipolar II disorder is diagnosed when an individual has a history of at least one hypomanic episode and at least one depressive episode. The typical course of the disorder is characterized by recurrent depressive and hypomanic episodes. Onset of bipolar type II most often occurs during the mid-twenties. The number of lifetime episodes tends to be higher for bipolar II disorder than for major depressive disorder of bipolar I disorder.

Cyclothymic disorder is diagnosed when an individual experiences mood instability over an extended period of time characterized by numerous hypomanic and depressive periods. The symptoms are present for more days than not, and there is no history of manic or mixed episodes. The course of cyclothymic disorder is often gradual and persistent, and onset commonly occurs during adolescence of early adulthood.

Rapid cycling is not a subtype of bipolar disorder but instead is a qualifier. It is defined as the presence of at least four mood episodes in the previous 12 months that meet the criteria for a manic, hypomanic, of major depressive episode. Rapid cycling is associated with an increased risk of suicide and tends to be precipitated by stressors such as life events, alcohol abuse, use of antidepressants, and medical disorders.

Overall, the diagnosis of bipolar disorder requires careful evaluation of an individual’s symptoms and history. Treatment typically involves a combination of medication and psychotherapy.

The Cochrane review in 2011 found that both comprehensive and non-comprehensive psychotherapies can have beneficial effects for individuals with borderline personality disorder (BPD) core pathology and associated general psychopathology. Dialectical Behaviour Therapy (DBT) was found to be particularly helpful, with results indicating a decrease in inappropriate anger, a reduction in self-harm, and an improvement in general functioning. However, there were generally too few studies to draw firm conclusions about the value of other types of psychotherapeutic interventions. Overall, more research is needed in this area.

Personality Disorder (Borderline)

History and Terminology

The term borderline personality disorder originated from early 20th-century theories that the disorder was on the border between neurosis and psychosis. The term borderline was coined by Adolph Stern in 1938. Subsequent attempts to define the condition include Otto Kernberg’s borderline personality organization, which identified key elements such as ego weakness, primitive defense mechanisms, identity diffusion, and unstable reality testing.

Features

The DSM-5 and ICD-11 both define borderline personality disorder as a pervasive pattern of instability in interpersonal relationships, self-image, and affects, and marked impulsivity. Symptoms include efforts to avoid abandonment, unstable relationships, impulsivity, suicidal behavior, affective instability, chronic feelings of emptiness, difficulty controlling temper, and transient dissociative symptoms.

Abuse

Childhood abuse and neglect are extremely common among borderline patients, with up to 87% having suffered some form of trauma. The effect of abuse seems to depend on the stage of psychological development at which it takes place.

comorbidity

Borderline PD patients are more likely to receive a diagnosis of major depressive disorder, bipolar disorder, panic disorder, PTSD, OCD, eating disorders, and somatoform disorders.

Psychological Therapy

Dialectical Behavioral Therapy (DBT), Mentalization-Based Treatment (MBT), Schema-Focused Therapy (SFT), and Transference-Focused Psychotherapy (TFP) are the main psychological treatments for BPD. DBT is the most well-known and widely available, while MBT focuses on improving mentalization, SFT generates structural changes to a patient’s personality, and TFP examines dysfunctional interpersonal dynamics that emerge in interactions with the therapist in the transference.

NICE Guidelines

The NICE guidelines on BPD offer very little recommendations. They do not recommend medication for treatment of the core symptoms. Regarding psychological therapies, they make reference to DBT and MBT being effective but add that the evidence base is too small to draw firm conclusions. They do specifically say Do not use brief psychotherapeutic interventions (of less than 3 months’ duration) specifically for borderline personality disorder of for the individual symptoms of the disorder.

Violence and aggression can be managed through rapid tranquillisation, although the evidence base for this approach is not strong. Different guidelines provide varying recommendations for rapid tranquillisation, including NICE, Maudsley Guidelines, and the British Association for Psychopharmacology (BAP). NICE recommends using IM lorazepam of IM haloperidol + IM promethazine for rapid tranquillisation in adults, taking into account factors such as previous response and patient preference. BAP provides a range of options for oral, inhaled, IM, and IV medications, including inhaled loxapine, buccal midazolam, and oral antipsychotics. Maudsley Guidelines suggest using oral lorazepam, oral promethazine, of buccal midazolam if prescribed a regular antipsychotic, of oral olanzapine, oral risperidone, of oral haloperidol if not already taking an antipsychotic. IM options include lorazepam, promethazine, olanzapine, aripiprazole, and haloperidol, although drugs should not be mixed in the same syringe. Haloperidol should ideally be used with promethazine to reduce the risk of dystonia.

Epidemiology of Mental Disorders Among the Elderly

Depression:
Contrary to popular belief, studies have shown that rates of depression among the elderly in the general population are lower than in younger adults. However, elderly individuals who seek medical attention have a higher prevalence of depressive symptoms, with one study in London reporting a point prevalence of around 30%. Suicide risk factors in the elderly include a history of attempts, depressive disorder, access to lethal means, physical illness of disability, chronic pain, recent losses, and social isolation. Physician education in recognizing and treating depression and restricting access to lethal means have been found to reduce suicide rates.

Personality Disorder:
There is limited information on the prevalence of personality disorders in the general population, but rates tend to decrease with age.

Psychosis:
Very late-onset schizophrenia, with onset after the age of 60, has a 1-year prevalence of 0.1 to 0.5%. It is more common in women and has been associated with sensory impairment. Genetic factors appear to be less important than in earlier onset schizophrenia.

Alcohol Misuse:
Studies have shown that men have higher rates of alcohol misuse than women in the elderly population. However, precise figures and prevalence rates are unreliable, and standard assessment tools may not be valid in this group.

Dementia:
Dementia incidence is similar across all continents and regions of the world, with Alzheimer’s accounting for 60-70% and vascular dementia accounting for 15-20% of all dementia cases. Age is the strongest risk factor for dementia, with approximately 48% of people aged 95 and over having dementia.

Brief Psychodynamic Psychotherapy: A Time-Limited Treatment

Brief psychodynamic psychotherapy is a type of therapy that is based on psychodynamic principles and is designed to be completed within a limited time frame, typically 10-12 sessions. This therapy is particularly effective when there is a specific focus of problem that the patient is dealing with. However, it is important that the patient is highly motivated and able to think in feeling terms for the therapy to be successful.

There are different subtypes of brief psychodynamic psychotherapy, and some factors are considered contraindications for this type of therapy. These include serious suicide attempts, substance abuse, and marked acting out. Overall, brief psychodynamic psychotherapy can be a useful tool for addressing specific issues and helping patients achieve their therapeutic goals within a limited time frame.

The likelihood of developing PTSD is greater for females. Additionally, experiencing significant distress and dissociation during the initial traumatic event are also linked to the development of PTSD.

Stress disorders, such as Post Traumatic Stress Disorder (PTSD), are emotional reactions to traumatic events. The diagnosis of PTSD requires exposure to an extremely threatening of horrific event, followed by the development of a characteristic syndrome lasting for at least several weeks, consisting of re-experiencing the traumatic event, deliberate avoidance of reminders likely to produce re-experiencing, and persistent perceptions of heightened current threat. Additional clinical features may include general dysphoria, dissociative symptoms, somatic complaints, suicidal ideation and behaviour, social withdrawal, excessive alcohol of drug use, anxiety symptoms, and obsessions of compulsions. The emotional experience of individuals with PTSD commonly includes anger, shame, sadness, humiliation, of guilt. The onset of PTSD symptoms can occur at any time during the lifespan following exposure to a traumatic event, and the symptoms and course of PTSD can vary significantly over time and individuals. Key differentials include acute stress reaction, adjustment disorder, and complex PTSD. Management of PTSD includes trauma-focused cognitive behavioral therapy (CBT), eye movement desensitization and reprocessing (EMDR), and supported trauma-focused computerized CBT interventions. Drug treatments, including benzodiazepines, are not recommended for the prevention of treatment of PTSD in adults, but venlafaxine of a selective serotonin reuptake inhibitor (SSRI) may be considered for adults with a diagnosis of PTSD if the person has a preference for drug treatment. Antipsychotics such as risperidone may be considered in addition if disabling symptoms and behaviors are present and have not responded to other treatments. Psychological debriefing is not recommended for the prevention of treatment of PTSD. For children and young people, individual trauma-focused CBT interventions of EMDR may be considered, but drug treatments are not recommended.

When substance misuse is considered, the majority of harmful actions towards others are not attributed primarily to mental illness. Additionally, individuals with mental illness of intellectual disability are at a higher risk of being subjected to violence rather than being the ones who commit violent acts.

Homicide is classified into three categories in England and Wales: murder, manslaughter, and infanticide. Murder requires intent to kill of cause grievous bodily harm, while manslaughter can be voluntary of involuntary. Mental disorder is significantly associated with homicide, particularly in people diagnosed with schizophrenia and personality disorder. Homicide rates by people with a mental disorder are based on calculations of those with disposals such as ‘diminished responsibility’ and ‘not guilty by reason of insanity’. The age-standardised rate for homicide in people with schizophrenia is estimated to be around 0.1 / 100,000, which translates to about 20-30 mental disorder homicides each year in England and Wales. However, a significant proportion of these cases tend to have a secondary diagnosis of alcohol / drug dependence. Individuals with schizophrenia commit 5-6% of homicides in England.

Mechanisms of action for illicit drugs can be classified based on their effects on ionotropic receptors of ion channels, G coupled receptors, of monoamine transporters. Cocaine and amphetamine both increase dopamine levels in the synaptic cleft, but through different mechanisms. Cocaine directly blocks the dopamine transporter, while amphetamine binds to the transporter and increases dopamine efflux through various mechanisms, including inhibition of vesicular monoamine transporter 2 and monoamine oxidase, and stimulation of the intracellular receptor TAAR1. These mechanisms result in increased dopamine levels in the synaptic cleft and reuptake inhibition.

Standard Deviation and Standard Error of the Mean

Standard deviation (SD) and standard error of the mean (SEM) are two important statistical measures used to describe data. SD is a measure of how much the data varies, while SEM is a measure of how precisely we know the true mean of the population. The normal distribution, also known as the Gaussian distribution, is a symmetrical bell-shaped curve that describes the spread of many biological and clinical measurements.

68.3% of the data lies within 1 SD of the mean, 95.4% of the data lies within 2 SD of the mean, and 99.7% of the data lies within 3 SD of the mean. The SD is calculated by taking the square root of the variance and is expressed in the same units as the data set. A low SD indicates that data points tend to be very close to the mean.

On the other hand, SEM is an inferential statistic that quantifies the precision of the mean. It is expressed in the same units as the data and is calculated by dividing the SD of the sample mean by the square root of the sample size. The SEM gets smaller as the sample size increases, and it takes into account both the value of the SD and the sample size.

Both SD and SEM are important measures in statistical analysis, and they are used to calculate confidence intervals and test hypotheses. While SD quantifies scatter, SEM quantifies precision, and both are essential in understanding and interpreting data.

Aetiology of Intellectual Disability

Intellectual disability (ID), previously known as learning disability, affects between 1% and 3% of the global population. The severity of ID varies, with mild cases being the most common, affecting around 85% of those with the condition. Moderate, severe, and profound cases affect 10%, 4%, and 2% of the population, respectively. The cause of ID can be attributed to environmental and/of genetic factors, although up to 60% of cases have no identifiable cause. Genetic factors are responsible for 25-50% of cases, with the likelihood increasing with the severity of the condition. Down Syndrome is the most common genetic cause of ID, while Fragile X syndrome is the most common X-linked cause and the second most common genetic cause of learning difficulty. Foetal alcohol syndrome is the most common acquired form of ID.

Motivational Interviewing: A Model for Resolving Ambivalence and Facilitating Change

Motivational interviewing (MI) is an evidence-based method used for people with substance misuse problems. It was introduced by William Miller in 1983, based on his experience with alcoholics. MI focuses on exploring and resolving ambivalence and centres on the motivational process that facilitates change. It is based on three key elements: collaboration, evocation, and autonomy.

There are four principles of MI: expressing empathy, supporting self-efficacy, rolling with resistance, and developing discrepancy. MI involves the use of micro-counseling skills called OARS, which stands for open-ended questions, affirmations, reflections, and summaries.

Change talk is defined as statements by the client that reveal consideration of, motivation for, of commitment to change. In MI, the therapist aims to guide the client to expression of change talk. Types of change talk can be remembered by the mnemonic DARN-CAT, which stands for desire, ability, reason, need, commitment, activation, and taking steps.

Overall, MI is a model for resolving ambivalence and facilitating change that emphasizes collaboration, evocation, and autonomy. It is a useful tool for therapists working with clients with substance misuse problems.

Korsakoff’s syndrome is characterized by a significant and disproportionate loss of the ability to form new memories, known as anterograde amnesia, in an otherwise cognitively intact individual (Caulo 2005). Additionally, individuals with this syndrome may experience source amnesia, where they can recall information but cannot remember where of how they learned it, as well as prosopamnesia, which is the inability to recognize of remember faces.

Korsakoff’s Syndrome

Korsakoff’s Syndrome, also known as amnesic syndrome, is a chronic condition that affects recent and anterograde memory in an alert and responsive patient. It is caused by prolonged thiamine (vitamin B1) deficiency and often follows Wernicke’s encephalopathy. The syndrome is characterized by a lack of insight, apathy, and confabulation. Thiamine is essential for glucose metabolism in the brain, and its deficiency leads to a toxic buildup of glucose, causing neuronal loss. The Mammillary bodies are the main areas affected in Korsakoff’s syndrome.

While intelligence on the WAIS is preserved, episodic memory is severely affected in Korsakoff’s syndrome. Semantic memory is variably affected, but implicit aspects of memory, such as response to priming and procedural memory, are preserved. Immediate memory tested with the digit span is normal, but information can only be retained for a few minutes at most. Patients with Korsakoff’s syndrome often display apathy, lack of initiative, and profound lack of insight.

Source: Kopelman M (2009) The Korsakoff Syndrome: Clinical Aspects, Psychology and Treatment. Alcohol and Alcoholism 44 (2): 148-154.

Antipsychotics and Hypertension

Clozapine is the antipsychotic that is most commonly linked to hypertension. However, it is important to note that essential hypertension is not a contraindication for any antipsychotic medication. Therefore, no antipsychotics should be avoided in patients with essential hypertension.

PANDAS: A Disorder Linked to Streptococcal Infections

PANDAS, of Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections, is a condition that affects children who develop sudden onset of obsessive-compulsive disorder (OCD) and/of tic disorders like Tourette’s Syndrome after contracting strep infections such as Strep throat of Scarlet Fever. The National Institute of Mental Health (NIMH) has identified five criteria for diagnosing PANDAS, including the presence of OCD and/of tic disorder, pediatric onset of symptoms, episodic course of symptom severity, association with group A Beta-hemolytic streptococcal infection, and association with neurological abnormalities. The anti streptococcal DNAse B (Anti DNAse-B) titre is commonly used to determine if there is immunologic evidence of a previous strep infection. PANDAS is linked to basal ganglia dysfunction.

Understanding Specific Phobia: Diagnosis, Course, and Treatment

A specific phobia is a type of anxiety disorder characterized by an intense fear of anxiety about a particular object of situation that is out of proportion to the actual danger it poses. This fear of anxiety is evoked almost every time the individual comes into contact with the phobic stimulus, and they actively avoid it of experience intense fear of anxiety if they cannot avoid it. Specific phobias usually develop in childhood, with situational phobias having a later onset than other types. Although most specific phobias develop in childhood, they can develop at any age, often due to traumatic experiences.

Exposure therapy is the current treatment of choice for specific phobias, involving in-vivo of imaging approaches to phobic stimuli of situations. Pharmacotherapy is not commonly used, but glucocorticoids and D-cycloserine have been found to be effective. Systematic desensitization, developed by Wolpe, was the first behavioral approach for phobias, but subsequent research found that exposure was the crucial variable for eliminating phobias. Graded exposure therapy is now preferred over flooding, which is considered unnecessarily traumatic. Only a small percentage of people with specific phobias receive treatment, possibly due to the temporary relief provided by avoidance.

Understanding Vitamin B12 Deficiency

Vitamin B12 deficiency is a common condition, especially among older adults, and can lead to various psychiatric symptoms. This water-soluble vitamin occurs in three different forms in the human body, and it is absorbed in the terminal ileum after binding with intrinsic factor. Vitamin B12 is a cofactor for two important metabolic reactions, and its deficiency can cause the accumulation of precursors, which can be diagnosed by measuring homocysteine and methylmalonic acid. Common dietary sources of vitamin B12 include meat, fish, and dairy products, and deficiency can be caused by decreased intake, poor absorption, intrinsic factor deficiency, chronic pancreatic disease, parasites, intestinal disease, of metabolic impairment. Symptoms of vitamin B12 deficiency are often nonspecific and can include weakness, fatigue, irritability, developmental delay/regression, paresthesias, anemia, and more. Neurologic changes can occur without hematologic abnormality.

Fonagy and Bateman – Mentalisation-Based Treatment

Mentalisation-Based Treatment (MBT) was developed by Peter Fonagy and Anthony Bateman in the 1990s. It is a psychodynamic therapy that focuses on improving the patient’s ability to mentalise, which is the capacity to understand one’s own and others’ mental states. MBT is primarily used to treat borderline personality disorder, but it has also been used to treat other mental health conditions.

Fonagy and Bateman work on MBT was influenced by their research on attachment theory and the importance of early relationships in shaping mentalisation abilities. They believed that individuals with borderline personality disorder have difficulties with mentalisation due to early attachment disruptions, and that MBT could help them develop more stable and secure relationships.

MBT is typically delivered in a group of individual format, and it involves a combination of psychoeducation, cognitive-behavioral techniques, and psychodynamic interventions. The therapist helps the patient to identify and reflect on their thoughts, feelings, and behaviors, and to understand how these are influenced by their past experiences and relationships. The therapist also helps the patient to develop more adaptive coping strategies and to improve their interpersonal skills.

Overall, Fonagy and Bateman work on MBT has contributed to the development of psychodynamic therapies that are more focused on specific treatment goals and evidence-based practices.

The distinction between interval and ratio scales is illustrated by the fact that ratio scales have a non-arbitrary zero point and meaningful ratios between values. Celsius and Fahrenheit temperature measurements are examples of interval scales, while the Kelvin scale is a ratio scale due to its zero point representing the complete absence of heat and the meaningful ratios between its values.

Scales of Measurement in Statistics

In the 1940s, Stanley Smith Stevens introduced four scales of measurement to categorize data variables. Knowing the scale of measurement for a variable is crucial in selecting the appropriate statistical analysis. The four scales of measurement are ratio, interval, ordinal, and nominal.

Ratio scales are similar to interval scales, but they have true zero points. Examples of ratio scales include weight, time, and length. Interval scales measure the difference between two values, and one unit on the scale represents the same magnitude on the trait of characteristic being measured across the whole range of the scale. The Fahrenheit scale for temperature is an example of an interval scale.

Ordinal scales categorize observed values into set categories that can be ordered, but the intervals between each value are uncertain. Examples of ordinal scales include social class, education level, and income level. Nominal scales categorize observed values into set categories that have no particular order of hierarchy. Examples of nominal scales include genotype, blood type, and political party.

Data can also be categorized as quantitative of qualitative. Quantitative variables take on numeric values and can be further classified into discrete and continuous types. Qualitative variables do not take on numerical values and are usually names. Some qualitative variables have an inherent order in their categories and are described as ordinal. Qualitative variables are also called categorical of nominal variables. When a qualitative variable has only two categories, it is called a binary variable.

Risk Factors for Delirium

Delirium is a common condition that affects many elderly individuals. There are several risk factors that can increase the likelihood of developing delirium. These risk factors include age, cognitive impairment, severe medical illness, previous history of delirium of neurological disease, psychoactive drug use, polypharmacy, and anticholinergic drug use.

Medications are the most common reversible cause of delirium and dementia in the elderly. Certain classes of drugs, such as opioids, benzodiazepines, and anticholinergics, are strongly associated with the development of drug-induced dementia. Long-acting benzodiazepines are more troublesome than shorter-acting ones. Opioids are associated with an approximately 2-fold increased risk of delirium in medical and surgical patients. Pethidine, a member of the opioid class, appears to have a higher risk of delirium compared with other opioids due to its accumulation in individuals with impaired renal function and conversion to a metabolite with anticholinergic properties.

Overall, it is important to be aware of these risk factors and to carefully monitor medication use in elderly individuals to prevent the development of delirium.

Elderly prisoners have a higher rate of depression, estimated at around 30%, compared to younger adult prisoners and community studies of the elderly in the UK. The risk of depression is even higher in prisoners with a history of psychiatric illness and those who report poor physical health. For more information, see the study by Fazel et al. (2001) titled Hidden psychiatric morbidity in elderly prisoners in the British Journal of Psychiatry.

The NICE Guideline recommends family therapy as the primary treatment option. For adults, guided self-help is the preferred first-line option, while medications are not advised for either children of adults.

Eating Disorders: NICE Guidelines

Anorexia:
For adults with anorexia nervosa, consider individual eating-disorder-focused cognitive behavioural therapy (CBT-ED), Maudsley Anorexia Nervosa Treatment for Adults (MANTRA), of specialist supportive clinical management (SSCM). If these are not acceptable, contraindicated, of ineffective, consider eating-disorder-focused focal psychodynamic therapy (FPT). For children and young people, consider anorexia-nervosa-focused family therapy (FT-AN) of individual CBT-ED. Do not offer medication as the sole treatment.

Bulimia:
For adults, the first step is an evidence-based self-help programme. If this is not effective, consider individual CBT-ED. For children and young people, offer bulimia-nervosa-focused family therapy (FT-BN) of individual CBT-ED. Do not offer medication as the sole treatment.

Binge Eating Disorder:
The first step is a guided self-help programme. If this is not effective, offer group of individual CBT-ED. For children and young people, offer the same treatments recommended for adults. Do not offer medication as the sole treatment.

Advice for those with eating disorders:
Encourage people with an eating disorder who are vomiting to avoid brushing teeth immediately after vomiting, rinse with non-acid mouthwash, and avoid highly acidic foods and drinks. Advise against misusing laxatives of diuretics and excessive exercise.

Additional points:
Do not offer physical therapy as part of treatment. Consider bone mineral density scans after 1 year of underweight in children and young people, of 2 years in adults. Do not routinely offer oral of transdermal oestrogen therapy to treat low bone mineral density in children of young people with anorexia nervosa. Consider transdermal 17-β-estradiol of bisphosphonates for women with anorexia nervosa.

Note: These guidelines are taken from NICE guidelines 2017.

You don’t need to concern yourself with the specifics of the various means. Simply keep in mind that the arithmetic mean is the one utilized in fundamental biostatistics.

Measures of Central Tendency

Measures of central tendency are used in descriptive statistics to summarize the middle of typical value of a data set. There are three common measures of central tendency: the mean, median, and mode.

The median is the middle value in a data set that has been arranged in numerical order. It is not affected by outliers and is used for ordinal data. The mode is the most frequent value in a data set and is used for categorical data. The mean is calculated by adding all the values in a data set and dividing by the number of values. It is sensitive to outliers and is used for interval and ratio data.

The appropriate measure of central tendency depends on the measurement scale of the data. For nominal and categorical data, the mode is used. For ordinal data, the median of mode is used. For interval data with a normal distribution, the mean is preferable, but the median of mode can also be used. For interval data with skewed distribution, the median is used. For ratio data, the mean is preferable, but the median of mode can also be used for skewed data.

In addition to measures of central tendency, the range is also used to describe the spread of a data set. It is calculated by subtracting the smallest value from the largest value.

Avoidant-restrictive food intake disorder can manifest in individuals of all ages, with some cases beginning in early childhood while others may present in older children, adolescents, of adults. Both males and females can be affected by this condition, which is characterized by a pattern of restricted eating and significantly low body weight, leading to similar health-related consequences as seen in anorexia nervosa. The key difference is that in anorexia nervosa, the desire for thinness of fear of weight gain is the primary motivator for maintaining an abnormally low body weight.

Eating disorders are a serious mental health condition that can have severe physical and psychological consequences. The ICD-11 lists several types of eating disorders, including Anorexia Nervosa, Bulimia Nervosa, Binge Eating Disorder, Avoidant-Restrictive Food Intake Disorder, Pica, and Rumination-Regurgitation Disorder.

Anorexia Nervosa is characterized by significantly low body weight, a persistent pattern of restrictive eating of other behaviors aimed at maintaining low body weight, excessive preoccupation with body weight of shape, and marked distress of impairment in functioning. Bulimia Nervosa involves frequent episodes of binge eating followed by inappropriate compensatory behaviors to prevent weight gain, excessive preoccupation with body weight of shape, and marked distress of impairment in functioning. Binge Eating Disorder is characterized by frequent episodes of binge eating without compensatory behaviors, marked distress of impairment in functioning, and is more common in overweight and obese individuals. Avoidant-Restrictive Food Intake Disorder involves avoidance of restriction of food intake that results in significant weight loss of impairment in functioning, but is not motivated by preoccupation with body weight of shape. Pica involves the regular consumption of non-nutritive substances, while Rumination-Regurgitation Disorder involves intentional and repeated regurgitation of previously swallowed food.

It is important to seek professional help if you of someone you know is struggling with an eating disorder. Treatment may involve a combination of therapy, medication, and nutritional counseling.

While there is no specific law against possessing steroids, it is considered unlawful to produce, distribute, of import/export steroids with the intention of supplying them without proper licensing. Those found guilty of such actions may face a maximum sentence of 14 years imprisonment and/of a substantial monetary penalty.

Drug Misuse (Law and Scheduling)

The Misuse of Drugs Act (1971) regulates the possession and supply of drugs, classifying them into three categories: A, B, and C. The maximum penalty for possession varies depending on the class of drug, with Class A drugs carrying a maximum sentence of 7 years.

The Misuse of Drugs Regulations 2001 further categorizes controlled drugs into five schedules. Schedule 1 drugs are considered to have no therapeutic value and cannot be lawfully possessed of prescribed, while Schedule 2 drugs are available for medical use but require a controlled drug prescription. Schedule 3, 4, and 5 drugs have varying levels of restrictions and requirements.

It is important to note that a single drug can have multiple scheduling statuses, depending on factors such as strength and route of administration. For example, morphine and codeine can be either Schedule 2 of Schedule 5.

Overall, the Misuse of Drugs Act and Regulations aim to regulate and control the use of drugs in the UK, with the goal of reducing drug misuse and related harm.

The only symptom that indicates hypoactive delirium is facial inexpression, while the rest of the symptoms suggest hyperactive delirium.

Delirium (also known as acute confusional state) is a condition characterized by a sudden decline in consciousness and cognition, with a particular impairment in attention. It often involves perceptual disturbances, abnormal psychomotor activity, and sleep-wake cycle impairment. Delirium typically develops over a few days and has a fluctuating course. The causes of delirium are varied, ranging from metabolic disturbances to medications. It is important to differentiate delirium from dementia, as delirium has a brief onset, early disorientation, clouding of consciousness, fluctuating course, and early psychomotor changes. Delirium can be classified into three subtypes: hypoactive, hyperactive, and mixed. Patients with hyperactive delirium demonstrate restlessness, agitation, and hyper vigilance, while those with hypoactive delirium present with lethargy and sedation. Mixed delirium demonstrates both hyperactive and hypoactive features. The hypoactive form is most common in elderly patients and is often misdiagnosed as depression of dementia.

Schizophrenia: Understanding the Risk Factors

Social class is a significant risk factor for schizophrenia, with people of lower socioeconomic status being more likely to develop the condition. Two hypotheses attempt to explain this relationship, one suggesting that environmental exposures common in lower social class conditions are responsible, while the other suggests that people with schizophrenia tend to drift towards the lower class due to their inability to compete for good jobs.

While early studies suggested that schizophrenia was more common in black populations than in white, the current consensus is that there are no differences in rates of schizophrenia by race. However, there is evidence that rates are higher in migrant populations and ethnic minorities.

Gender and age do not appear to be consistent risk factors for schizophrenia, with conflicting evidence on whether males of females are more likely to develop the condition. Marital status may also play a role, with females with schizophrenia being more likely to marry than males.

Family history is a strong risk factor for schizophrenia, with the risk increasing significantly for close relatives of people with the condition. Season of birth and urban versus rural place of birth have also been shown to impact the risk of developing schizophrenia.

Obstetric complications, particularly prenatal nutritional deprivation, brain injury, and influenza, have been identified as significant risk factors for schizophrenia. Understanding these risk factors can help identify individuals who may be at higher risk for developing the condition and inform preventative measures.

As an AI language model, I do not have personal opinions of beliefs. However, I can provide information and guidance on the standards of reporting for different types of research studies. The guidelines mentioned above are essential for ensuring that research studies are reported accurately and transparently, which is crucial for the scientific community to evaluate and replicate the findings. It is important for researchers to be familiar with these standards and follow them when reporting their studies to ensure the quality and integrity of their research.

The risk of obstetric complications is about twice as high in individuals with schizophrenia compared to those without the condition.

Schizophrenia and Migration: A Meta-Analysis and Review

Migration is a significant risk factor for the development of schizophrenia, according to a comprehensive review of the topic. The study found that the mean weighted relative risk for first-generation migrants was 2.7, while the relative risk for second-generation migrants was 4.5. When analyzing both first- and second-generation migrants, the relative risk was 2.9. The study also found that migrants from developing countries and areas with a majority black population had significantly greater effect sizes. These findings highlight the importance of considering migration status when assessing risk for schizophrenia.

EMDR: A Trauma-Focused Therapy for PTSD

EMDR, of eye movement desensitisation and reprocessing, is a therapy developed by Francine Shapiro in the 1980s that focuses on processing traumatic memories. While the exact way it works is not fully understood, it involves reliving traumatic memories while experiencing bilateral alternating stimulation, often through a light source. EMDR is recommended by the NICE Guidelines as a treatment for PTSD, along with trauma-focused cognitive-behavioral therapy.

Sedatives and Liver Disease

Sedatives are commonly used for their calming effects, but many of them are metabolized in the liver. Therefore, caution must be taken when administering sedatives to patients with liver disease. The Maudsley Guidelines recommend using low doses of the following sedatives in patients with hepatic impairment: lorazepam, oxazepam, temazepam, and zopiclone. It is important to note that zopiclone should also be used with caution and at low doses in this population. Proper management of sedative use in patients with liver disease can help prevent further damage to the liver and improve overall patient outcomes.

PET scans reveal the level of metabolic activity in different parts of the brain. In individuals with Alzheimer’s disease, the temporoparietal cortices exhibit decreased metabolic activity as a result of the atrophy in those regions.

Dementia is a condition that can be diagnosed and supported with the use of neuroimaging techniques. In Alzheimer’s disease, MRI and CT scans are used to assess volume changes in specific areas of the brain, such as the mesial temporal lobe and temporoparietal cortex. SPECT and PET scans can also show functional changes, such as hypoperfusion and glucose hypometabolism. Vascular dementia can be detected with CT and MRI scans that show atrophy, infarcts, and white matter lesions, while SPECT scans reveal a patchy multifocal pattern of hypoperfusion. Lewy body dementia tends to show nonspecific and subtle changes on structural imaging, but SPECT and PET scans can reveal posterior deficits and reduced D2 receptor density. Frontotemporal dementia is characterized by frontal lobe atrophy, which can be seen on CT and MRI scans, while SPECT scans show anterior perfusion deficits. NICE recommends the use of MRI for early diagnosis and detection of subcortical vascular changes, SPECT for differentiating between Alzheimer’s disease, vascular dementia, and frontotemporal dementia, and DaTscan for establishing a diagnosis of dementia with Lewy bodies.

Understanding the Kappa Statistic for Measuring Interobserver Variation

The kappa statistic, also known as Cohen’s kappa coefficient, is a useful tool for quantifying the level of agreement between independent observers. This measure can be applied in any situation where multiple observers are evaluating the same thing, such as in medical diagnoses of research studies. The kappa coefficient ranges from 0 to 1, with 0 indicating complete disagreement and 1 indicating perfect agreement. By using the kappa statistic, researchers and practitioners can gain insight into the level of interobserver variation present in their data, which can help to improve the accuracy and reliability of their findings. Overall, the kappa statistic is a valuable tool for understanding and measuring interobserver variation in a variety of contexts.

Consistent evidence suggests a link between cannabis use and schizophrenia risk, with the risk increasing as the age of first use decreases.

Schizophrenia and Cannabis Use

The relationship between cannabis use and the risk of developing schizophrenia is a topic of ongoing debate. However, research suggests that cannabis use may increase the risk of later schizophrenia of schizophreniform disorder by two-fold (Arseneault, 2004). The risk of developing schizophrenia appears to be higher in individuals who start using cannabis at a younger age. For instance, regular cannabis smokers at the age of 15 are 4.5 times more likely to develop schizophrenia at the age of 26, compared to those who did not report regular use until age 18 (Murray, 2004).

A systematic review published in the Lancet in 2007 found that the lifetime risk of developing psychosis increased by 40% in individuals who had ever used cannabis (Moore, 2007). Another meta-analysis reported that the age at onset of psychosis was 2.70 years younger in cannabis users than in non-users (Large, 2011). These findings suggest that cannabis use may have a significant impact on the development of schizophrenia and related disorders.

Antidepressants and Diabetes

Depression is a prevalent condition among patients with diabetes. It is crucial to select the appropriate antidepressant as some may have negative effects on weight and glucose levels. The first-line treatment for depression in diabetic patients is selective serotonin reuptake inhibitors (SSRIs), with fluoxetine having the most supporting data. Serotonin-norepinephrine reuptake inhibitors (SNRIs) are also likely to be safe, but there is less evidence to support their use. Tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOIs) should be avoided. These recommendations are based on the Maudsley Guidelines 10th Edition.

Dosages of donepezil exceeding 10 mg are not recommended, as his Alzheimer’s has advanced from mild to moderate. NICE recommends incorporating memantine alongside an AChE-I at this stage.

Treatment of Dementia: AChE Inhibitors and Memantine

Dementia is a debilitating condition that affects millions of people worldwide. Acetylcholinesterase inhibitors (AChE inhibitors) and memantine are two drugs used in the management of dementia. AChE inhibitors prevent cholinesterase from breaking down acetylcholine, which is deficient in Alzheimer’s due to loss of cholinergic neurons. Donepezil, galantamine, and rivastigmine are AChE inhibitors used in the management of Alzheimer’s. Memantine is an NMDA receptor antagonist that blocks the effects of pathologically elevated levels of glutamate that may lead to neuronal dysfunction.

NICE guidelines recommend the use of AChE inhibitors for managing mild to moderate Alzheimer’s and memantine for managing moderate to severe Alzheimer’s. For those already taking an AChE inhibitor, memantine can be added if the disease is moderate of severe. AChE inhibitors are also recommended for managing mild, moderate, and severe dementia with Lewy bodies, while memantine is considered if AChE inhibitors are not tolerated of contraindicated. AChE inhibitors and memantine are not recommended for vascular dementia, frontotemporal dementia, of cognitive impairment due to multiple sclerosis.

The British Association for Psychopharmacology recommends AChE inhibitors as the first choice for Alzheimer’s and mixed dementia, while memantine is the second choice. AChE inhibitors and memantine are also recommended for dementia with Parkinson’s and dementia with Lewy bodies.

In summary, AChE inhibitors and memantine are important drugs used in the management of dementia. The choice of drug depends on the type and severity of dementia, as well as individual patient factors.

Normality Testing in Statistics

In statistics, parametric tests are based on the assumption that the data set follows a normal distribution. On the other hand, non-parametric tests do not require this assumption but are less powerful. To check if a distribution is normally distributed, there are several tests available, including the Kolmogorov-Smirnov (Goodness-of-Fit) Test, Jarque-Bera test, Wilk-Shapiro test, P-plot, and Q-plot. However, it is important to note that if a data set is not normally distributed, it may be possible to transform it to make it follow a normal distribution, such as by taking the logarithm of the values.

The statistical significance of the result is questionable as the confidence interval encompasses values below 100. This implies that there is a possibility that the actual value could be lower than 100, which contradicts the observed value of 120 indicating a rise in mortality in this population.

Calculation of Standardised Mortality Ratio (SMR)

To calculate the SMR, age and sex-specific death rates in the standard population are obtained. An estimate for the number of people in each category for both the standard and study populations is needed. The number of expected deaths in each age-sex group of the study population is calculated by multiplying the age-sex-specific rates in the standard population by the number of people in each category of the study population. The sum of all age- and sex-specific expected deaths gives the expected number of deaths for the whole study population. The observed number of deaths is then divided by the expected number of deaths to obtain the SMR.

The SMR can be standardised using the direct of indirect method. The direct method is used when the age-sex-specific rates for the study population and the age-sex-structure of the standard population are known. The indirect method is used when the age-specific rates for the study population are unknown of not available. This method uses the observed number of deaths in the study population and compares it to the number of deaths that would be expected if the age distribution was the same as that of the standard population.

The SMR can be interpreted as follows: an SMR less than 1.0 indicates fewer than expected deaths in the study population, an SMR of 1.0 indicates the number of observed deaths equals the number of expected deaths in the study population, and an SMR greater than 1.0 indicates more than expected deaths in the study population (excess deaths). It is sometimes expressed after multiplying by 100.

Negative predictive value = 172 / 177

Clinical tests are used to determine the presence of absence of a disease of condition. To interpret test results, it is important to have a working knowledge of statistics used to describe them. Two by two tables are commonly used to calculate test statistics such as sensitivity and specificity. Sensitivity refers to the proportion of people with a condition that the test correctly identifies, while specificity refers to the proportion of people without a condition that the test correctly identifies. Accuracy tells us how closely a test measures to its true value, while predictive values help us understand the likelihood of having a disease based on a positive of negative test result. Likelihood ratios combine sensitivity and specificity into a single figure that can refine our estimation of the probability of a disease being present. Pre and post-test odds and probabilities can also be calculated to better understand the likelihood of having a disease before and after a test is carried out. Fagan’s nomogram is a useful tool for calculating post-test probabilities.

The most crucial factor in Hill’s criteria for causation is temporality, of the temporal relationship between exposure and outcome. It is imperative that the exposure to a potential causal factor, such as factor ‘A’, always occurs before the onset of the disease. This criterion is the only absolute requirement for causation. The other criteria include the strength of the relationship, dose-response relationship, consistency, plausibility, consideration of alternative explanations, experimental evidence, specificity, and coherence.

Phototherapy, also known as light therapy, has been extensively studied for its use in treating seasonal affective disorder (SAD) of winter depression. The treatment involves sitting next to a bright light for 1-2 hours. A 2005 meta-analysis of randomized, controlled trials found that bright light treatment is effective, with results equivalent to most antidepressant pharmacotherapy trials. However, the National Institute for Health and Care Excellence (NICE) advises that the evidence for the efficacy of light therapy is uncertain for those with winter depression. Light therapy has also been found to be effective in treating non-seasonal depression and ADHD. The type and strength of light that works best and the timing of the therapy remain unclear. It is important for the light to enter the eye, so it cannot be delivered while a person is asleep. (Golden, 2005).