New-Onset Psychosis in a Patient With Recent Stimulant Use
A 24-year-old college senior is brought to the clinic by his roommate after 5 days of decreased sleep (about 2 hours per night), rapid speech, and the belief that campus police are monitoring his laptop. He has no prior psychiatric history and no known family history. He reports using prescribed amphetamine salts for ADHD for 3 years, but admits to taking 'double or triple' his dose during finals week and using a friend's vape containing an unknown substance twice in the past week. Vitals: HR 118, BP 148/92, temp 37.6 C, pupils 6 mm and reactive. He is oriented to person, place, and year, but is tangential and intermittently appears to respond to internal stimuli. Urine drug screen is positive for amphetamines only. He denies suicidal or homicidal ideation but cannot describe a safe discharge plan.
1. What is your leading diagnostic formulation, and what features push you toward or away from a primary psychotic disorder such as schizophrenia or bipolar I disorder at this visit?
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Leading formulation: substance/medication-induced psychotic disorder (amphetamine), with a differential of stimulant-induced mania.
Features supporting a substance/medication-induced etiology:
- Temporal relationship: symptoms began during escalating stimulant use and after exposure to an unknown vaped substance.
- Physiologic signs: tachycardia, hypertension, mydriasis, and reduced sleep are consistent with sympathomimetic toxicity.
- No prior psychiatric history and no known family history lowers (but does not eliminate) the pre-test probability of a primary psychotic or bipolar disorder.
Features that keep primary psychosis or bipolar I on the differential:
- The symptom cluster (decreased need for sleep, pressured speech, paranoid delusions) fits a manic episode; mania can be triggered or unmasked by stimulants.
- A single visit cannot establish the required duration criteria. Substance-induced psychosis typically resolves within days to weeks of abstinence, whereas schizophrenia requires continuous disturbance for ≥6 months and bipolar requires a discrete mood episode with its own duration criteria.
Practical conclusion: Do not anchor a chronic psychotic or bipolar diagnosis on this encounter. Document a working diagnosis of substance/medication-induced psychotic disorder, initiate abstinence from stimulants, and plan reassessment after a period of sustained abstinence. If psychosis persists well beyond expected clearance, or if a full manic syndrome emerges independent of substance use, the diagnosis must be revised.
2. The patient is hemodynamically stable but cannot give a safe plan. What is the appropriate level of care and immediate management, and how do you justify it?
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Level of care: emergency/acute psychiatric evaluation, not routine outpatient follow-up.
Justification:
- He has impaired judgment and insight (cannot describe a safe plan) plus persecutory delusions, which create risk of impulsive behavior.
- Medical stabilization first: the sympathomimetic picture (HR 118, BP 148/92) warrants medical monitoring, so a combined emergency department/psychiatric setting is appropriate rather than a standalone outpatient plan.
- Denies SI/HI is reassuring but does not by itself permit discharge when insight and judgment are impaired.
Immediate management:
- Stop the amphetamine and arrange supervised withdrawal/monitoring.
- Treat agitation/psychosis symptomatically if needed; avoid adding stimulants or agents that worsen tachycardia without medical input.
- Obtain collateral from the roommate and, with consent or per emergency provisions, prior records.
- Labs/medical workup as indicated (electrolytes, renal/hepatic function, ECG given tachycardia) to exclude other causes.
- Safety plan and disposition coordinated with the emergency team; document capacity assessment.
The exam-tested judgment: risk and inability to self-care drive disposition more than the specific label on the psychosis.