AKT-1810

A 55-year-old man presents to his General Practitioner reporting ongoing distress following the sudden death of his wife 12 months ago following a cardiac arrest. He took three months off work to ‘deal with’ his wife’s death and then returned to his full-time role. He lives alone and reports that he has been unable to ‘bounce back’. He thinks of his wife’s death often and it distresses and distracts him. He has been sleeping poorly, has missed several shifts and was finally dismissed from his job. He feels isolated and a sense of responsibility that he did not ‘look after his wife’.
What is the most likely underlying diagnosis?