Psychiatry and Behavioral Sciences: Recognition, Risk and Psychotropic Harm
The Psychiatry and Behavioral Sciences domain tests recognition and management of major psychiatric illness, the mental state examination, psychotropic adverse effects, and the interface between psychiatry and general medicine.
Core rules
- Mental state examination: appearance, behaviour, speech, mood and affect, thought form and content, perception, cognition, insight.
- Major depression: at least five of nine symptoms for at least two weeks, including depressed mood or anhedonia, causing impairment.
- Bipolar disorder: mania requires elevated or irritable mood plus increased energy for at least one week with three (or four if irritable) of grandiosity, reduced sleep, pressured speech, flight of ideas, distractibility, increased goal-directed activity and risky behaviour.
- Schizophrenia: at least two of delusions, hallucinations, disorganised speech, grossly disorganised or catatonic behaviour, negative symptoms, for at least six months with at least one month of active symptoms, with functional decline.
- Serotonin syndrome: clonus, hyperreflexia, agitation, hyperthermia, diarrhoea - rapid onset after serotonergic agents; stop the drug, give benzodiazepines, consider cyproheptadine.
- Neuroleptic malignant syndrome: lead-pipe rigidity, bradyreflexia, altered consciousness, fever, raised CK, autonomic instability - stop the antipsychotic, use dantrolene or bromocriptine, supportive care.
- Lithium toxicity: tremor, ataxia, confusion, vomiting; precipitated by dehydration, NSAIDs, ACE inhibitors and thiazides.
- Capacity: understand, retain, weigh and communicate; capacity is decision-specific and separate from insight or detention under mental health law.
Worked example
A 26-year-old on sertraline is started on tramadol and within 24 hours develops agitation, sweating, temperature 38.2 °C, inducible ankle clonus and hyperreflexia. This is serotonin syndrome: onset is rapid and neuromuscular signs dominate. The serotonergic agents are stopped, benzodiazepines given for agitation, and cyproheptadine considered. NMS would instead show lead-pipe rigidity, bradyreflexia and a raised CK evolving over days.
Traps
- Starting an antidepressant alone in bipolar disorder and triggering mania.
- Missing delirium (acute onset, fluctuating attention) in an elderly patient labelled as depressed or demented.
- Confusing capacity with compliance or insight.
- Attributing extrapyramidal symptoms to anxiety and missing acute dystonia.