OMSB Psychiatry (OEPSY) cheat sheet

Psychiatry - Core Clinical Reference

• Delirium: acute onset, fluctuating attention/awareness, altered cognition; manage by treating the underlying cause, orienting measures, and antipsychotics only for severe agitation or psychosis (avoid in Parkinson disease and Lewy body dementia).

• Major depressive disorder requires ≥5 of 9 symptoms for ≥2 weeks with functional impairment; at least one symptom must be depressed mood or anhedonia. First-line: SSRI, SNRI, mirtazapine, or bupropion; psychotherapy equally effective in mild-moderate illness.

• Serotonin syndrome triad: mental status change, autonomic hyperactivity, neuromuscular hyperactivity (clonus, hyperreflexia); onset within 24 h of serotonergic agent or dose increase. Stop offending agents; cyproheptadine for moderate-severe cases.

• Neuroleptic malignant syndrome: rigidity (lead-pipe), hyperthermia >38 °C, autonomic instability, elevated CK, leukocytosis; onset over 1-3 days. Stop antipsychotic, supportive care, dantrolene or bromocriptine.

• Lithium: therapeutic 0.6-1.0 mmol/L (0.4-0.8 in elderly); monitor renal and thyroid function every 6 months; toxicity signs include coarse tremor, ataxia, vomiting, confusion. Avoid NSAIDs, thiazides, ACE inhibitors; avoid in pregnancy (Ebstein anomaly).

• Acute dystonia: within hours-days of dopamine antagonist; treat with anticholinergic (benztropine, procyclidine) or diphenhydramine. Akathisia: within days-weeks; reduce dose, add beta-blocker or benzodiazepine. Tardive dyskinesia: after months-years; consider VMAT2 inhibitor (valbenazine, deutetrabenazine).

• Alcohol withdrawal: CIWA-Ar-guided benzodiazepines; thiamine before glucose; monitor for delirium tremens (48-96 h), seizures (6-48 h). Wernicke encephalopathy triad: confusion, ophthalmoplegia, ataxia.

• Capacity assessment: patient must understand, appreciate, reason, and express a choice. Capacity is decision-specific and can be present for one decision and absent for another; a diagnosis of mental illness does not by itself negate capacity.

• Suicide risk assessment: inquire about ideation, plan, intent, means, prior attempts, access to firearms, protective factors; highest risk in the weeks after psychiatric discharge and in older men. Safety planning and means restriction reduce risk.