Psychiatry and Behavioral Medicine
Core concepts
Major depression, bipolar disorder, schizophrenia spectrum illness, anxiety disorders, substance use and withdrawal, delirium, suicide risk assessment, and psychopharmacology. Depression requires at least five symptoms for two weeks with functional impairment; bipolar disorder requires a manic or hypomanic episode, and antidepressants alone can trigger mania. Serotonin syndrome is a triad of mental status change, autonomic instability, and neuromuscular hyperactivity; neuroleptic malignant syndrome shows rigidity, fever, and elevated creatine kinase. Alcohol withdrawal is treated with benzodiazepines and thiamine before glucose.
Traps
- Prescribing an antidepressant alone in bipolar depression.
- Missing suicide risk in an older man with new insomnia and hopelessness.
- Confusing serotonin syndrome with NMS or anticholinergic toxicity.
- Giving glucose before thiamine in a malnourished patient.
- Overlooking medical causes of psychosis, such as thyroid disease, drugs, or delirium.
- Using antipsychotics as first-line treatment for insomnia in older adults.
Worked example
A 30-year-old on sertraline is started on a second serotonergic agent and presents with agitation, clonus, hyperreflexia, fever, and diarrhea. This is serotonin syndrome. Stop the serotonergic drugs and provide supportive care; benzodiazepines treat agitation, and cyproheptadine is considered in severe cases. Rule of thumb: clonus and hyperreflexia point to serotonin; lead-pipe rigidity and marked CK elevation point to NMS.