DO Psychiatry and Behavioral Medicine 2 — Questions and Answers
Question 1: A 40-year-old woman with depression is started on fluoxetine. What is the primary mechanism of action of SSRIs?
- Inhibition of monoamine oxidase
- Blockade of postsynaptic dopamine receptors
- Inhibition of serotonin reuptake at the presynaptic terminal (Correct answer)
- Stimulation of GABA-A receptors
Correct answer: Inhibition of serotonin reuptake at the presynaptic terminal
SSRIs block the serotonin transporter (SERT), preventing reuptake of serotonin into the presynaptic neuron and increasing serotonin availability in the synaptic cleft.
Question 2: A patient on lithium for bipolar disorder presents with coarse tremor, confusion, ataxia, and nausea. His serum lithium level is 2.1 mEq/L. What is the most appropriate immediate management?
- Increase the lithium dose to achieve therapeutic levels
- Add a low-dose antipsychotic to control symptoms
- Discontinue lithium and provide supportive care with hydration (Correct answer)
- Administer activated charcoal and a cathartic
Correct answer: Discontinue lithium and provide supportive care with hydration
Lithium toxicity (levels >1.5 mEq/L with symptoms) requires immediate discontinuation and supportive care; the therapeutic range is 0.6–1.2 mEq/L.
Question 3: A 25-year-old woman presents with intense fear of abandonment, markedly unstable relationships alternating between idealization and devaluation, identity disturbance, recurrent self-harm, and severe emotional lability. What is the most likely diagnosis?
- Histrionic Personality Disorder
- Narcissistic Personality Disorder
- Borderline Personality Disorder (Correct answer)
- Antisocial Personality Disorder
Correct answer: Borderline Personality Disorder
Borderline Personality Disorder is characterized by fear of abandonment, unstable relationships, identity disturbance, impulsivity, and recurrent self-harm or suicidal behavior.
Question 4: A patient with alcohol use disorder is admitted for detoxification. During which timeframe after the last drink is the risk for alcohol withdrawal seizures highest?
- 1–6 hours after last drink
- 6–24 hours after last drink
- 24–48 hours after last drink (Correct answer)
- 5–7 days after last drink
Correct answer: 24–48 hours after last drink
Alcohol withdrawal seizures most commonly occur 24–48 hours after the last drink; delirium tremens typically peaks at 48–72 hours.
Question 5: A patient taking haloperidol develops hyperthermia (40.5°C), severe lead-pipe muscle rigidity, altered consciousness, and autonomic instability. CPK is markedly elevated. What is this condition?
- Serotonin Syndrome
- Neuroleptic Malignant Syndrome (Correct answer)
- Malignant Hyperthermia
- Anticholinergic Toxicity
Correct answer: Neuroleptic Malignant Syndrome
Neuroleptic Malignant Syndrome is a life-threatening antipsychotic reaction presenting with hyperthermia, lead-pipe rigidity, altered consciousness, and autonomic instability with elevated CPK.
Question 6: An adult patient reports longstanding difficulty sustaining attention, frequent task-switching, forgetfulness, and disorganization present since childhood that impairs occupational functioning. What is the first-line pharmacological treatment for adult ADHD?
- Bupropion
- Atomoxetine
- Amphetamine salts or methylphenidate (Correct answer)
- Modafinil
Correct answer: Amphetamine salts or methylphenidate
Stimulants (amphetamine salts or methylphenidate) are first-line pharmacological treatments for ADHD in both adults and children due to their superior efficacy.
Question 7: A 55-year-old woman presents with excessive worry about multiple life domains occurring more days than not for 8 months, with associated muscle tension, fatigue, and irritability. What is the minimum duration of symptoms required to diagnose Generalized Anxiety Disorder?
- 2 weeks
- 1 month
- 6 months (Correct answer)
- 1 year
Correct answer: 6 months
DSM-5 requires excessive anxiety and worry occurring more days than not for at least 6 months for a diagnosis of Generalized Anxiety Disorder.
DO Psychiatry and Behavioral Medicine 2
A 40-year-old woman with depression is started on fluoxetine.
What is the primary mechanism of action of SSRIs?