Psychiatry Flashcards

A 34-year-old woman with bipolar I disorder is stable on lithium (serum level 0.9 mEq/L) and becomes pregnant. She has had three prior severe manic episodes requiring hospitalization. Which of the following is the most appropriate management strategy?

Answer: Continue lithium at the lowest effective dose with enhanced fetal monitoring, given the high relapse risk outweighs teratogenic risk

In a patient with severe bipolar I disorder and multiple hospitalizations, the risk of relapse without a mood stabilizer is substantial and may itself harm the fetus through behaviors, poor self-care, or medication exposures during a manic episode. Lithium carries a small absolute risk of Ebstein's anomaly (relative risk ~1.5–2×, absolute risk ~0.1%), which is lower than previously believed. Valproate has a much higher teratogenic profile (neural tube defects ~1–2%, significant cognitive teratogenicity) and is generally contraindicated in pregnancy. Carbamazepine also carries neural tube defect risk (~0.5–1%). Antipsychotic monotherapy may be insufficient for severe bipolar I. The benefit-risk analysis favors continuing lithium with fetal echocardiography at 16–18 weeks.

A 58-year-old man presents with a 4-month history of visual hallucinations depicting small animals and children, mild cognitive decline, and REM sleep behavior disorder. His motor examination reveals mild cogwheel rigidity. Which neuropathological finding is most likely to be present at autopsy?

Answer: Alpha-synuclein Lewy bodies in the neocortex, limbic system, and brainstem

This clinical picture — visual hallucinations of people/animals, mild parkinsonism, cognitive decline, and REM sleep behavior disorder — is classic for Dementia with Lewy Bodies (DLB). The neuropathological hallmark is alpha-synuclein aggregates forming Lewy bodies throughout the neocortex, limbic structures, and brainstem. REM sleep behavior disorder is a prodromal marker of synucleinopathies. Neurofibrillary tangles/plaques characterize Alzheimer's disease (though some overlap exists). TDP-43 inclusions typify frontotemporal lobar degeneration. Prion deposits with spongiform change occur in Creutzfeldt-Jakob disease, which presents more acutely with rapid decline.

A patient on clozapine develops a sudden fever of 39.2°C, severe throat pain, and a WBC of 900/μL with an absolute neutrophil count (ANC) of 400/μL on day 18 of therapy. What is the correct immediate action?

Answer: Discontinue clozapine immediately, initiate broad-spectrum antibiotics and G-CSF, and never re-challenge with clozapine

An ANC < 500/μL (severe neutropenia/agranulocytosis) requires immediate and permanent discontinuation of clozapine. This is a potentially life-threatening emergency requiring hospitalization, broad-spectrum antibiotics for febrile neutropenia, and granulocyte colony-stimulating factor (G-CSF, e.g., filgrastim). Clozapine-induced agranulocytosis carries a mortality risk of ~3–4% without prompt treatment. Re-challenge with clozapine is absolutely contraindicated after confirmed agranulocytosis (ANC < 500/μL), as rechallenge carries a very high risk of recurrence and death. Dose reduction or temporary holds are not appropriate — the REMS program mandates permanent discontinuation.

A 27-year-old man is brought to the ED after ingesting an unknown substance. He is agitated, diaphoretic, has a temperature of 40.1°C, muscle rigidity, hyperreflexia with clonus (more prominent in the lower extremities), and mydriasis. Heart rate is 148 bpm. He was recently started on linezolid for a wound infection and takes sertraline 100 mg daily. Which of the following best explains his presentation?

Answer: Serotonin syndrome precipitated by the pharmacodynamic interaction between sertraline and linezolid

This presentation is classic for serotonin syndrome: hyperthermia, agitation, diaphoresis, clonus (particularly lower extremity > upper extremity), hyperreflexia, tachycardia, and mydriasis. The key pharmacological interaction is that linezolid is a reversible, non-selective MAO inhibitor — when combined with an SSRI (sertraline), it creates excess serotonergic activity. This is a well-recognized but often missed drug interaction. NMS typically has lead-pipe rigidity, bradyreflexia, and slower onset (hours to days). Anticholinergic syndrome features dry flushed skin, absent bowel sounds, and urinary retention without clonus. Malignant hyperthermia requires exposure to volatile anesthetics or succinylcholine and presents with hypercarbia, not clonus.

A psychiatrist is treating a 45-year-old woman with treatment-resistant MDD who has failed four adequate antidepressant trials. She has no history of mania or hypomania. The clinician is considering augmentation strategies. Which of the following statements about lithium augmentation in treatment-resistant unipolar depression is most accurate?

Answer: Lithium augmentation has the strongest historical evidence base among augmentation strategies for treatment-resistant unipolar MDD, with response typically seen within 2–6 weeks

Lithium augmentation of antidepressants in treatment-resistant unipolar MDD has one of the longest evidence bases of any augmentation strategy, with response rates of 40–60% in early studies. It typically requires 2–6 weeks to see response at therapeutic levels (0.6–0.9 mEq/L for augmentation — not necessarily the higher mood stabilizer levels). While atypical antipsychotic augmentation has more recent RCT data and is widely used, lithium augmentation remains a guideline-supported, evidence-based option and should not be considered a last resort. Lithium does not 'convert' patients to bipolar disorder. The antidepressant augmentation target level is generally 0.6–0.9 mEq/L, not above 1.2 mEq/L (which raises toxicity risk).

A 32-year-old man with schizophrenia has been stable on haloperidol for 3 years. He develops repetitive, involuntary lip-smacking, tongue protrusion, and choreiform hand movements that persist even after his antipsychotic dose is reduced. The AIMS score is 8. He is highly distressed by the movements. Which FDA-approved treatment is most appropriate for his condition?

Answer: Prescribe valbenazine, a selective VMAT2 inhibitor approved for tardive dyskinesia in adults

Tardive dyskinesia (TD) with significant distress and an AIMS score of 8 warrants treatment with an FDA-approved agent. Valbenazine (Ingrezza) and deutetrabenazine (Austedo) are the two FDA-approved treatments specifically for TD in adults. Valbenazine is a highly selective VMAT2 inhibitor that reduces dopamine release in the striatum. Benztropine and other anticholinergics may actually worsen TD and are not recommended. While clozapine may modestly suppress TD movements and is preferred if antipsychotic change is needed, it does not eliminate TD reliably within 4 weeks and carries its own risks. Tetrabenazine is FDA-approved for chorea of Huntington's disease — NOT specifically for tardive dyskinesia (that distinction belongs to valbenazine and deutetrabenazine).