Systematic workup of new-onset or acute exacerbation of psychotic symptoms to identify medical, substance, and primary psychiatric causes.
Also known as: acute psychosis, first-episode psychosis, new-onset psychosis
Overview
Acute onset or exacerbation of psychotic symptoms — delusions, hallucinations, disorganized thought, grossly disorganized/catatonic behavior, or negative symptoms — requiring urgent evaluation to distinguish primary psychiatric, substance-induced, and medical/neurologic etiologies, and to initiate safe and effective management.
Epidemiology
First-episode psychosis incidence ~15-30 per 100,000/year. Peak onset late teens through 30s; men present 3-5 years earlier than women. Acute exacerbations common in established schizophrenia, schizoaffective disorder, bipolar I, and severe MDD.
Try two board-style Acute Psychosis Evaluation questions
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Question 1PsychiatryMedium
A 19-year-old man has 2 months of social withdrawal, declining grades, talking to himself, laughing inappropriately, and believing his roommate is an FBI agent. Urine toxicology is negative. Which of the following is the most appropriate initial pharmacotherapy?
AClozapine
BSertraline
CLithium
DLorazepam
ERisperidone
Reveal answer & full explanation
Correct answer: E — Risperidone
AClozapine
BSertraline
CLithium
DLorazepam
ERisperidone✓
Why risperidone is correct
This patient presents with first-episode psychosis: 2 months of positive symptoms including delusions (believing roommate is an FBI agent), hallucinations (talking to himself), and disorganized behavior (laughing inappropriately)
Initial pharmacotherapy for first-episode psychosis is a second-generation antipsychotic such as risperidone or aripiprazole
Coordinated specialty care combining medication, psychotherapy, family psychoeducation, and supported education is most effective
Duration of untreated psychosis correlates with worse outcomes
Why the others are wrong
Sertraline — a selective serotonin reuptake inhibitor; treats depression/anxiety, not psychosis
Lithium — a mood stabilizer used in bipolar disorder; not indicated for first-episode psychosis without a clear mood component
Lorazepam — a benzodiazepine; may provide short-term agitation control but is not a primary antipsychotic treatment
Clozapine — the most effective antipsychotic for schizophrenia, but reserved for treatment-resistant illness after adequate trials of two other antipsychotics or for persistent suicidality because of its risks of severe neutropenia, seizures, myocarditis, and metabolic effects; it is not initial therapy for first-episode psychosis
Question 2PsychiatryMedium
A 25-year-old male has a first episode of psychosis with auditory hallucinations, paranoid delusions, disorganized speech, and flat affect for 3 months. He uses cannabis. Brain MRI and labs are normal. He is started on risperidone. Which of the following pharmacologic strategies is most likely to reduce his risk of psychotic relapse?
AIntermittent antipsychotic dosing
BLong-acting injectable antipsychotic
CTwo concurrent oral antipsychotics
DContinued oral antipsychotic
EGuided antipsychotic dose reduction
Reveal answer & full explanation
Correct answer: B — Long-acting injectable antipsychotic
AIntermittent antipsychotic dosing
BLong-acting injectable antipsychotic✓
CTwo concurrent oral antipsychotics
DContinued oral antipsychotic
EGuided antipsychotic dose reduction
Why Long-acting injectable antipsychotic is correct
Medication non-adherence is the biggest driver of relapse in first-episode psychosis (FEP) — over 50% relapse within 5 years
Long-acting injectable (LAI) antipsychotics (aripiprazole lauroxil, paliperidone palmitate, risperidone microspheres) lower relapse and hospitalization compared with oral antipsychotics across randomized trials (pooled risk ratio about 0.88), with larger effects in mirror-image and real-world studies
After a first episode of schizophrenia, a randomized trial found far fewer relapses with LAI risperidone than with oral risperidone over 12 months (5% vs 33%; Subotnik 2015)
Why the others are wrong
Continued oral antipsychotic — continuous oral maintenance clearly lowers relapse compared with placebo or discontinuation, but partial or covert nonadherence is common after a first episode, especially with ongoing cannabis use, and LAIs lower relapse further than oral dosing in randomized trials
Two concurrent oral antipsychotics — antipsychotic polypharmacy is not recommended; does not improve outcomes and increases side effects
Intermittent antipsychotic dosing — randomized trials of prodrome-triggered intermittent treatment show higher relapse and rehospitalization rates than continuous maintenance therapy
Guided antipsychotic dose reduction — tempting because long-term follow-up of a first-episode trial linked early dose reduction with better functional recovery, but randomized trials of tapering or discontinuing antipsychotics after a first episode show more relapses than continuous maintenance treatment, so it raises rather than lowers his relapse risk
Additional high-yield points
Coordinated specialty care for FEP improves employment, school functioning, and symptoms, and reduces hospitalization
Treatment duration: minimum 1-2 years after first episode, often lifelong
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Sleep deprivation, postpartum (postpartum psychosis is a psychiatric emergency)
Pathophysiology
Final common pathway involves dysregulated mesolimbic dopaminergic signaling, with contributions from glutamatergic, GABAergic, serotonergic, and cholinergic systems depending on etiology. Inflammatory and structural mechanisms in delirium and autoimmune encephalitis.
Clinical presentation
Symptoms
Hallucinations (auditory most common in primary psychiatric; visual, tactile, olfactory raise concern for medical/substance etiology)
Mental status — orientation, attention (serial 7s, months backward; asterixis suggests metabolic encephalopathy) — inattention/clouded sensorium points to delirium
Differential diagnosis
Delirium — Acute onset, fluctuating course, inattention, altered consciousness — search for underlying medical cause
Substance-induced psychosis — Temporal relationship to use or withdrawal (stimulants, cannabis, hallucinogens, alcohol withdrawal); resolves with abstinence
Primary psychotic disorder — Schizophrenia, schizophreniform, schizoaffective, brief psychotic, delusional — by duration and pattern
Mood disorder with psychotic features — Mood congruent or incongruent psychosis confined to MDE or manic episode
Postpartum psychosis — Onset usually within the first 2 weeks postpartum; rapid mood/cognition shifts; strongest risk factors are personal or family history of bipolar disorder and prior postpartum psychosis; PSYCHIATRIC EMERGENCY due to suicide and infanticide risk
Diagnostic workup
Diagnostic criteria
Workup-driven differential. Delirium per DSM-5-TR requires disturbance in attention and awareness developing over hours to days with fluctuation and evidence of an underlying medical cause. Primary psychotic disorders categorized by duration and mood context (see Schizophrenia entry).
Labs
CBC, CMP (Ca, glucose), Mg, phosphate, LFTs
TSH, B12, folate; thiamine if malnourished
Urinalysis, urine drug screen (including fentanyl, synthetic cannabinoids if available)
Blood alcohol
Pregnancy test in women of reproductive age
Syphilis serology, HIV; consider hepatitis panel
ESR/CRP; ANA if autoimmune concern
Acetaminophen and salicylate levels if overdose possible
ECG (QTc baseline before antipsychotic, and especially for haloperidol, ziprasidone, IV antipsychotics)
Ammonia, ABG, lactate if metabolic encephalopathy suspected
LP if febrile, meningismus, immunocompromised, or autoimmune encephalitis suspected
Imaging
Non-contrast head CT in first-episode psychosis, focal neurologic findings, trauma, altered consciousness
MRI brain when feasible — higher sensitivity for demyelination, autoimmune encephalitis, structural lesions
EEG if seizure suspected or to evaluate encephalopathy / non-convulsive status epilepticus
Diagnostic algorithm
flowchart TD
A[Acute psychotic presentation] --> B[Stabilize and ensure safety<br/>vital signs, focused exam]
B --> C{Vital sign or<br/>neurologic abnormality?}
C -->|Yes| D[Workup for medical cause<br/>labs, head imaging, +/- LP/EEG]
C -->|No| L{"First episode, age >50,<br/>or atypical features?"}
L -->|Yes| M["Baseline medical workup<br/>CBC, CMP, TSH, B12, RPR, HIV,<br/>pregnancy test +/- neuroimaging"]
L -->|No| E[Targeted psychiatric +<br/>substance workup]
M -->|Cause found| G
M -->|Unrevealing| E
D --> F{Delirium / medical /<br/>autoimmune / infectious?}
F -->|Yes| G[Treat underlying cause<br/>+ supportive care]
F -->|No| H[Likely primary psychiatric]
E --> I{Substance present?}
I -->|Yes| J[Substance-induced<br/>reassess after abstinence]
I -->|No| H
H --> K[Antipsychotic +<br/>coordinated specialty care]
Acute psychosis triage from presentation to disposition.
Treatment
First-line
Stabilize ABC; protect patient and staff; ensure safe environment
Verbal de-escalation; offer oral medication before IM
Acute agitation: PO/IM olanzapine, risperidone, haloperidol (often + lorazepam) — avoid combining IM olanzapine + IM benzodiazepine due to respiratory depression risk
Treat underlying cause — correct hypoglycemia, electrolytes, infection; benzodiazepines for alcohol withdrawal; physostigmine for severe anticholinergic toxicity in select cases; immunotherapy for autoimmune encephalitis
Antipsychotic for primary psychotic disorder once medical causes addressed — risperidone, olanzapine, aripiprazole, quetiapine
Admit involuntarily if necessary to protect from self-harm or harm to others
Reduce stimulation; address sleep; involve family for collateral and supports
Low-dose antipsychotic for severe agitation/safety; avoid in alcohol/benzo withdrawal (use benzodiazepines)
Avoid benzodiazepines as routine delirium treatment (worsens delirium except in withdrawal states)
First-episode primary psychosis
Coordinated specialty care — case management, family education, supported employment
Antipsychotic with favorable metabolic and EPS profile; shared decision-making
Address substance use, particularly cannabis
Engage family early; provide long-term follow-up
Postpartum psychosis
Psychiatric emergency — inpatient admission with mother-infant safety planning
Antipsychotic, mood stabilizer (often lithium), benzodiazepine for agitation; ECT highly effective and rapid
Address breastfeeding considerations and infant safety
Second-line / adjunct
ECT for refractory or catatonic presentations, severe MDD with psychosis, postpartum psychosis
Long-acting injectable antipsychotics — lower relapse and rehospitalization than oral maintenance; offer if adherence is poor or uncertain or the patient prefers them (APA 2020), including early in first-episode psychosis
Clozapine for treatment-resistant primary psychotic disorder
Address ongoing substance use with MOUD/AUD treatment as appropriate
Complications
Self-harm or harm to others during acute phase
Neuroleptic malignant syndrome from antipsychotic — discontinue, supportive care, consider dantrolene/bromocriptine
QT prolongation, especially with IV haloperidol, ziprasidone, or polypharmacy
Iatrogenic worsening of delirium with benzodiazepines or anticholinergics
PANCE pearls
First-episode psychosis warrants thorough medical workup, including neuroimaging — do not assume primary psychiatric etiology.
Visual or tactile hallucinations, fluctuating attention, abnormal vitals, focal neuro findings, or age >50 with new psychosis should escalate medical workup.
Anti-NMDA receptor encephalitis classically affects young women (often with ovarian teratoma) — subacute behavioral change, seizures, dyskinesias, autonomic instability; LP shows CSF antibodies.
Postpartum psychosis is a psychiatric emergency — distinguish from postpartum depression and 'baby blues'; rapid cycling, suicidality, infanticidal thoughts require admission.
Do not use lorazepam IM with IM olanzapine (respiratory and cardiopulmonary depression risk); separate by >=1 hour.
In delirium, antipsychotics are for safety only — they do not shorten delirium duration.
References
APA 2020 — American Psychiatric Association Practice Guideline for the Treatment of Patients with Schizophrenia, 3rd ed. (2020)
Freudenreich 2009 — Freudenreich O, Schulz SC, Goff DC. Initial medical work-up of first-episode psychosis: a conceptual review. Early Interv Psychiatry 2009;3(1):10-18
Graus 2016 — Graus F et al. A clinical approach to diagnosis of autoimmune encephalitis. Lancet Neurol 2016
ACEP 2017 — American College of Emergency Physicians. Clinical Policy: Critical Issues in the Diagnosis and Management of the Adult Psychiatric Patient in the Emergency Department. Ann Emerg Med 2017;69(4):480-498
DSM-5-TR — American Psychiatric Association. DSM-5-TR (2022)
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