Psychiatry: Safety, Differential Diagnosis, and Medication Pitfalls
Psychiatry: safety first, then syndrome
Psychiatric assessment starts with safety: suicide risk, violence risk, withdrawal, and medical causes of altered mental status. High-yield concepts include major depression, bipolar disorder, schizophrenia, anxiety disorders, substance intoxication and withdrawal, delirium, dementia, and psychotropic adverse effects. New confusion in a hospitalized patient is delirium until proven otherwise; identify infection, medications, hypoxia, pain, retention, and withdrawal. In depression, screen for bipolar disorder before starting an antidepressant because antidepressant monotherapy can precipitate mania or rapid cycling. In psychosis, distinguish primary psychotic illness from substance-induced and medical causes.
Traps
Do not equate capacity with agreeing to treatment; capacity requires understanding, appreciation, reasoning, and choice. Do not miss serotonin syndrome or neuroleptic malignant syndrome. Benzodiazepine and alcohol withdrawal can be life-threatening; treat with benzodiazepines and thiamine when indicated. Avoid tricyclic antidepressants in overdose-prone patients.
Worked rule
If a patient with bipolar disorder presents depressed, avoid antidepressant monotherapy; use a mood stabilizer and consider coordinated psychiatric care. If a patient on an SSRI develops agitation, hyperreflexia, clonus, and fever, stop serotonergic drugs and manage serotonin syndrome.