Measures of Disease Frequency: Incidence and Prevalence

Incidence and prevalence are two important measures of disease frequency. Incidence measures the speed at which new cases of a disease are emerging, while prevalence measures the burden of disease within a population. Cumulative incidence and incidence rate are two types of incidence measures, while point prevalence and period prevalence are two types of prevalence measures.

Cumulative incidence is the average risk of getting a disease over a certain period of time, while incidence rate is a measure of the speed at which new cases are emerging. Prevalence is a proportion and is a measure of the burden of disease within a population. Point prevalence measures the number of cases in a defined population at a specific point in time, while period prevalence measures the number of identified cases during a specified period of time.

It is important to note that prevalence is equal to incidence multiplied by the duration of the condition. In chronic diseases, the prevalence is much greater than the incidence. The incidence rate is stated in units of person-time, while cumulative incidence is always a proportion. When describing cumulative incidence, it is necessary to give the follow-up period over which the risk is estimated. In acute diseases, the prevalence and incidence may be similar, while for conditions such as the common cold, the incidence may be greater than the prevalence.

Incidence is a useful measure to study disease etiology and risk factors, while prevalence is useful for health resource planning. Understanding these measures of disease frequency is important for public health professionals and researchers in order to effectively monitor and address the burden of disease within populations.

Mothers who commit neonaticide, which is the killing of a newborn within 24 hours, are typically younger than those who kill their older infants. While both boys and girls are equally at risk of neonaticide, boys are more likely to be victims of infant homicide.

Infant Homicide

Homicide is a significant contributor to infant mortality, with infants under 1 year of age being more likely to be victims of homicide than older children of the general population. Neonaticide, the killing of a baby within 24 hours of delivery, is different from the homicide of infants older than a day. Neonaticide is usually committed by the mother, who is often young, single, and living with her parents. The pregnancy is often unintentional and concealed, and the motivation to kill is usually because the child was unwanted. In contrast, the homicide of infants older than a day is more likely to be committed by a parent, with boys at greater risk than girls. Risk factors for the homicide of infants older than a day include younger age, family history of violence, violence in current relationships of the perpetrator, evidence of past abuse of neglect of children, and personality disorder and/of depression.

Paroxetine Use During Pregnancy: Is it Safe?

Prescribing medication during pregnancy and breastfeeding is challenging due to the potential risks to the fetus of baby. No psychotropic medication has a UK marketing authorization specifically for pregnant of breastfeeding women. Women are encouraged to breastfeed unless they are taking carbamazepine, clozapine, of lithium. The risk of spontaneous major malformation is 2-3%, with drugs accounting for approximately 5% of all abnormalities. Valproate and carbamazepine are associated with an increased risk of neural tube defects, and lithium is associated with cardiac malformations. Benzodiazepines are associated with oral clefts and floppy baby syndrome. Antidepressants have been linked to preterm delivery and congenital malformation, but most findings have been inconsistent. TCAs have been used widely without apparent detriment to the fetus, but their use in the third trimester is known to produce neonatal withdrawal effects. Sertraline appears to result in the least placental exposure among SSRIs. MAOIs should be avoided in pregnancy due to a suspected increased risk of congenital malformations and hypertensive crisis. If a pregnant woman is stable on an antipsychotic and likely to relapse without medication, she should continue the antipsychotic. Depot antipsychotics should not be offered to pregnant of breastfeeding women unless they have a history of non-adherence with oral medication. The Maudsley Guidelines suggest specific drugs for use during pregnancy and breastfeeding. NICE CG192 recommends high-intensity psychological interventions for moderate to severe depression and anxiety disorders. Antipsychotics are recommended for pregnant women with mania of psychosis who are not taking psychotropic medication. Promethazine is recommended for insomnia.

In adults with learning disability, ordering is the most prevalent compulsion, whereas hand-washing, checking, and cleaning are more common in the general population. The prevalence rate of OCD in learning disability is higher at 2.5% compared to the general population. However, it can be challenging to distinguish OCD from other behaviors associated with learning disability syndromes, such as tics, stereotyped behaviors, and autism spectrum disorder. Additionally, assessing obsessional thoughts in individuals with learning disability can be challenging due to their difficulty in articulating them.

Alcohol withdrawal is characterized by overactivity of the autonomic nervous system, resulting in symptoms such as agitation, tremors, sweating, nausea, vomiting, fever, and tachycardia. These symptoms typically begin 3-12 hours after drinking stops, peak between 24-48 hours, and can last up to 14 days. Withdrawal seizures may occur before blood alcohol levels reach zero, and a small percentage of people may experience delirium tremens (DT), which can be fatal if left untreated. Risk factors for DT include abnormal liver function, old age, severity of withdrawal symptoms, concurrent medical illness, heavy alcohol use, self-detox, previous history of DT, low potassium, low magnesium, and thiamine deficiency.

Pharmacologically assisted detox is often necessary for those who regularly consume more than 15 units of alcohol per day, and inpatient detox may be needed for those who regularly consume more than 30 units per day. The Clinical Institute Withdrawal Assessment of Alcohol Scale (CIWA-Ar) can be used to assess the severity of withdrawal symptoms and guide treatment decisions. Benzodiazepines are the mainstay of treatment, as chronic alcohol exposure results in decreased overall brain excitability and compensatory decrease of GABA-A neuroreceptor response to GABA. Chlordiazepoxide is a good first-line agent, while oxazepam, temazepam, and lorazepam are useful in patients with liver disease. Clomethiazole is effective but carries a high risk of respiratory depression and is not recommended. Thiamine should be offered to prevent Wernicke’s encephalopathy, and long-acting benzodiazepines can be used as prophylaxis for withdrawal seizures. Haloperidol is the treatment of choice if an antipsychotic is required.

The patient’s symptoms indicate possible viral encephalitis, likely caused by herpes. To confirm the diagnosis and rule out other infections, a diagnostic examination of the cerebrospinal fluid (CSF) is necessary. However, it is important to ensure the safety of the patient before performing the CSF examination, as there is a risk of herniation. Therefore, a CT scan of the head should be the initial investigation to be carried out, as it can also detect any abscesses that may be present.

– Diminished responsibility can only be applied in murder cases in English law
– It diminishes the defendant’s liability for their actions
– Criteria for diminished responsibility include:
– Abnormality of mental functioning caused by a recognised medical condition
– Impairment of mental ability to understand the nature of their conduct, form a rational judgement, of exercise self-control
– Advising that the defendant did not know the nature of their act refers to Not Guilty By Reason of Insanity
– Advising that the defendant cannot follow proceedings in court refers to Fitness to Plead
– Epilepsy has been used as a mental health defence in both Diminished Responsibility and Not Guilty by Reason of Insanity pleas in the past.

Schizophrenia in children is rare compared to adults, with a prevalence estimate of 0.05% for those under 15 years old. There are two classifications based on age of onset: early onset schizophrenia (EOS) when symptoms appear between 13-18 years old, and very early onset schizophrenia (VEOS) when symptoms appear at of before 13 years old. EOS and VEOS have atypical features compared to adult-onset schizophrenia, including insidious onset, more severe neurodevelopmental abnormalities, terrifying visual hallucinations, constant inappropriate of blunted affects, higher rates of familial psychopathology, minor response to treatment, and poorer outcomes. Preliminary data suggests that VEOS and EOS may be due to greater familial vulnerability from genetic, psychosocial, and environmental factors. Poor outcomes are most reliably linked to a positive history of premorbid difficulties, greater symptom severity (especially negative symptoms) at baseline, and longer duration of untreated psychosis. Age at psychosis onset and sex are not consistent predictors of outcome.

Melanie Klein, a prominent psychoanalyst, introduced two significant concepts in her work: the paranoid-schizoid position and the depressive position. The paranoid-schizoid position is a state of mind where the individual perceives the world as fragmented, dividing it into good and bad. This position is characterized by the defense mechanism of splitting, where the individual separates the good and bad aspects of themselves and others.

On the other hand, the depressive position follows the paranoid-schizoid position and is characterized by the ability to accept ambivalence, where something can be both good and bad. This position represents a more integrated state of mind, where the individual can hold conflicting emotions and thoughts simultaneously. These concepts have been influential in psychoanalytic theory and have contributed to our understanding of the human psyche.

Learning Disability and comorbid Psychiatric Illness

It is estimated that 30-50% of adults with learning disabilities also experience mental health problems, including problem behavior. Specific prevalence rates for various mental health disorders in this population have been identified through research. For example, psychotic disorders are present in 4% of adults with learning disabilities, while affective disorders are present in 6%. Autism is the most prevalent disorder, affecting 7.5% of this population.

It is important to note that major depressive disorder can occur at all IQ levels in people with learning disabilities, but may be missed of misinterpreted as challenging behavior. Additionally, individuals with learning disabilities are more susceptible to the negative effects of life events and may develop adjustment disorder. Post-traumatic stress disorder is also common in this population.

Stimulant drugs may be less effective in children with learning disabilities and should be used with caution in individuals with Tourette’s of autism, as they may trigger tics. Overall, it is crucial to recognize and address comorbid psychiatric illness in individuals with learning disabilities to ensure appropriate treatment and support.

Alcohol withdrawal is characterized by overactivity of the autonomic nervous system, resulting in symptoms such as agitation, tremors, sweating, nausea, vomiting, fever, and tachycardia. These symptoms typically begin 3-12 hours after drinking stops, peak between 24-48 hours, and can last up to 14 days. Withdrawal seizures may occur before blood alcohol levels reach zero, and a small percentage of people may experience delirium tremens (DT), which can be fatal if left untreated. Risk factors for DT include abnormal liver function, old age, severity of withdrawal symptoms, concurrent medical illness, heavy alcohol use, self-detox, previous history of DT, low potassium, low magnesium, and thiamine deficiency.

Pharmacologically assisted detox is often necessary for those who regularly consume more than 15 units of alcohol per day, and inpatient detox may be needed for those who regularly consume more than 30 units per day. The Clinical Institute Withdrawal Assessment of Alcohol Scale (CIWA-Ar) can be used to assess the severity of withdrawal symptoms and guide treatment decisions. Benzodiazepines are the mainstay of treatment, as chronic alcohol exposure results in decreased overall brain excitability and compensatory decrease of GABA-A neuroreceptor response to GABA. Chlordiazepoxide is a good first-line agent, while oxazepam, temazepam, and lorazepam are useful in patients with liver disease. Clomethiazole is effective but carries a high risk of respiratory depression and is not recommended. Thiamine should be offered to prevent Wernicke’s encephalopathy, and long-acting benzodiazepines can be used as prophylaxis for withdrawal seizures. Haloperidol is the treatment of choice if an antipsychotic is required.

Paroxetine Use During Pregnancy: Is it Safe?

Prescribing medication during pregnancy and breastfeeding is challenging due to the potential risks to the fetus of baby. No psychotropic medication has a UK marketing authorization specifically for pregnant of breastfeeding women. Women are encouraged to breastfeed unless they are taking carbamazepine, clozapine, of lithium. The risk of spontaneous major malformation is 2-3%, with drugs accounting for approximately 5% of all abnormalities. Valproate and carbamazepine are associated with an increased risk of neural tube defects, and lithium is associated with cardiac malformations. Benzodiazepines are associated with oral clefts and floppy baby syndrome. Antidepressants have been linked to preterm delivery and congenital malformation, but most findings have been inconsistent. TCAs have been used widely without apparent detriment to the fetus, but their use in the third trimester is known to produce neonatal withdrawal effects. Sertraline appears to result in the least placental exposure among SSRIs. MAOIs should be avoided in pregnancy due to a suspected increased risk of congenital malformations and hypertensive crisis. If a pregnant woman is stable on an antipsychotic and likely to relapse without medication, she should continue the antipsychotic. Depot antipsychotics should not be offered to pregnant of breastfeeding women unless they have a history of non-adherence with oral medication. The Maudsley Guidelines suggest specific drugs for use during pregnancy and breastfeeding. NICE CG192 recommends high-intensity psychological interventions for moderate to severe depression and anxiety disorders. Antipsychotics are recommended for pregnant women with mania of psychosis who are not taking psychotropic medication. Promethazine is recommended for insomnia.

Depression is a common occurrence after a stroke, affecting 30-40% of patients. The location of the stroke lesion can play a crucial role in the development of major depression. Treatment for post-stroke depression must take into account the cause of the stroke, medical comorbidities, and potential interactions with other medications. The Maudsley guidelines recommend SSRIs as the first-line treatment, with paroxetine being the preferred choice. Nortriptyline is also an option, as it does not increase the risk of bleeding. If the patient is on anticoagulants, citalopram and escitalopram may be preferred. Antidepressant prophylaxis has been shown to be effective in preventing post-stroke depression, with nortriptyline, fluoxetine, escitalopram, duloxetine, sertraline, and mirtazapine being effective options. Mianserin, however, appears to be ineffective.

According to NICE, it is recommended to gradually decrease the dose of lithium over a period of at least 4 weeks, and ideally up to 3 months, when discontinuing it, even if the individual has begun taking another antimanic medication.

Bipolar Disorder: Diagnosis and Management

Bipolar disorder is a lifelong condition characterized by episodes of mania or hypomania and episodes of depressed mood. The peak age of onset is 15-19 years, and the lifetime prevalence of bipolar I disorders is estimated to be around 2.1%. The diagnosis of bipolar disorder is based on the presence of manic or hypomanic episodes, which are characterized by elevated of expansive mood, rapid speech, and increased activity of energy. Psychotic symptoms, such as delusions and hallucinations, may also be present.

Bipolar depression differs from unipolar depression in several ways, including more rapid onset, more frequent episodes, and shorter duration. Rapid cycling is a qualifier that can be applied to bipolar I of bipolar II disorder and 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.

The management of bipolar disorder involves acute and long-term interventions. Acute management of mania or hypomania may involve stopping antidepressants and offering antipsychotics of mood stabilizers. Long-term management may involve psychological interventions and pharmacological treatments such as lithium, valproate, of olanzapine.

It is important to note that valproate should not be offered to women of girls of childbearing potential for long-term bipolar disorder unless other options are ineffective of not tolerated and a pregnancy prevention program is in place. Aripiprazole is recommended as an option for treating moderate to severe manic episodes in adolescents with bipolar I disorder.

Overall, the diagnosis and management of bipolar disorder require a comprehensive approach that takes into account the individual’s symptoms, history, and preferences.

Snowball sampling is a unique technique utilized in qualitative research when the desired sample trait is uncommon. In such cases, it can be challenging of expensive to locate suitable respondents. Snowball sampling involves existing subjects recruiting future subjects, which can help overcome these difficulties. For more information on this method, please refer to the additional resources provided.

ADHD (Diagnosis and Management in Children)

ADHD is a behavioural syndrome characterised by symptoms of inattention, hyperactivity, and impulsivity. The DSM-5 and ICD-11 provide diagnostic criteria for the condition, with both recognising three subtypes: predominantly inattentive, predominantly hyperactive-impulsive, and combined.

Treatment for children under 5 involves offering an ADHD-focused group parent-training programme as a first-line option. Medication should only be considered after obtaining advice from a specialist ADHD service. For children and young people aged 5-18, advice and support should be given, along with an ADHD-focused group parent-training programme. Medication should only be offered if ADHD symptoms persist after environmental modifications have been implemented and reviewed. Cognitive behavioural therapy may also be considered for those who have benefited from medication but still experience significant impairment.

NICE advises against elimination diets, dietary fatty acid supplementation, and the use of the ‘few foods diet’. Methylphenidate of lisdexamfetamine is the first-line medication option, with dexamphetamine considered for those who respond to lisdexamfetamine but cannot tolerate the longer effect profile. Atomoxetine of guanfacine may be offered for those who cannot tolerate methylphenidate of lisdexamfetamine. Clonidine and atypical antipsychotics should only be used with advice from a tertiary ADHD service.

Drug holidays may be considered for children and young people who have not met the expected height for their age due to medication. However, NICE advises that withdrawal from treatment is associated with a risk of symptom exacerbation.

Depression in Children and Adolescents

The first line of treatment for depression in children and adolescents is psychological therapy. If this approach is unsuccessful, fluoxetine is the preferred treatment. If fluoxetine is also ineffective, an alternative SSRI should be considered. However, there is limited data on which SSRI is most appropriate. These recommendations are based on the Maudsley Guidelines 10th Edition.

The 2017 NICE Guidelines advise clinicians to inform individuals with binge eating disorder that psychological treatments focused on addressing binge eating may not have a significant impact on body weight and that weight loss is not the primary goal of therapy. However, it is important to clarify that while CBT-ED does not specifically target weight loss, it can lead to weight reduction in the long run by addressing binge eating behaviors.

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.

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.

Simpson’s Paradox is a real phenomenon where the comparison of association between variables can change direction when data from multiple groups are merged into one. The other three options are not valid terms.

Types of Bias in Statistics

Bias is a systematic error that can lead to incorrect conclusions. Confounding factors are variables that are associated with both the outcome and the exposure but have no causative role. Confounding can be addressed in the design and analysis stage of a study. The main method of controlling confounding in the analysis phase is stratification analysis. The main methods used in the design stage are matching, randomization, and restriction of participants.

There are two main types of bias: selection bias and information bias. Selection bias occurs when the selected sample is not a representative sample of the reference population. Disease spectrum bias, self-selection bias, participation bias, incidence-prevalence bias, exclusion bias, publication of dissemination bias, citation bias, and Berkson’s bias are all subtypes of selection bias. Information bias occurs when gathered information about exposure, outcome, of both is not correct and there was an error in measurement. Detection bias, recall bias, lead time bias, interviewer/observer bias, verification and work-up bias, Hawthorne effect, and ecological fallacy are all subtypes of information bias.