Gangguan Psikotik Akut
Published on September 7, 2026
Risk Factors
Young adults (typically 20s–30s), female sex, psychosocial stressors (acute life events, bereavement, sudden loss), personality disorders (especially paranoid and borderline traits), immigration, low socioeconomic status, peripartum period
Etiology
No single confirmed cause. Conceptualized as a transient psychotic break precipitated by acute stress in a vulnerable individual. Neurobiologically, a sudden surge in dopaminergic activity is hypothesized. Distinct from the neurodevelopmental pathology of schizophrenia.
Presentation
Sudden onset of bizarre behavior, confusion, rapidly shifting delusions and hallucinations, emotional turbulence, and fluctuating consciousness. The patient was entirely well days to weeks ago.
Classic Exam
Disorganized behavior, rapidly changing affect (euphoria shifting to tearfulness within minutes), perplexity, fleeting delusions (persecution one hour, grandiosity the next), auditory or visual hallucinations that change in theme. No focal neurological deficit.
Diagnostics
Clinical diagnosis based on PPDGJ-III criteria. Labs (CBC, metabolic panel, thyroid function, urine toxicology, HIV, syphilis screening) and brain imaging (CT/MRI) are used to exclude organic causes, not to confirm the diagnosis.
Management
Low-dose antipsychotics (haloperidol or risperidone) for acute symptom control. Benzodiazepines for agitation. Brief hospitalization if safety is a concern. Taper and discontinue antipsychotics after full resolution. Psychoeducation and stress management for relapse prevention.
Keywords
"Acute onset," "within 2 weeks," "rapidly changing," "polymorphic symptoms," "emotional turmoil," "no prior psychiatric history," "full resolution," "preceded by acute stress"
01Pathophysiology
Acute and Transient Psychotic Disorders (F23) represent a category of psychoses defined not by a single pathological mechanism, but by a distinctive temporal pattern: an abrupt onset, a polymorphic and shifting clinical picture, and a generally favorable prognosis with full recovery.
The underlying neurobiology is incompletely understood, but the prevailing model involves a sudden, stress-induced dysregulation of dopaminergic neurotransmission in the mesolimbic pathway. Unlike schizophrenia, where structural brain changes and progressive neurodevelopmental abnormalities are present, F23 disorders are thought to reflect a transient functional disturbance. The brain's dopamine circuits become hyperactive in response to an overwhelming psychosocial stressor, producing hallucinations and delusions. Because the disturbance is functional rather than structural, the symptoms resolve completely once the neurochemical storm subsides.
The polymorphic nature of the symptoms (rapidly changing delusions, hallucinations that shift in type and intensity, and emotional states that swing from ecstasy to despair within the same day) is a direct consequence of this unstable neurochemical state. The brain's reality-testing apparatus is overwhelmed but not destroyed. This is why the patient can appear profoundly psychotic one hour and relatively lucid the next.
The role of acute psychosocial stress is central. PPDGJ-III recognizes that these disorders often follow a clearly identifiable life event (bereavement, job loss, relationship breakdown, migration) occurring within the two weeks preceding onset. The stress acts as a trigger in a predisposed individual, not as a sufficient cause on its own. This distinction is important: the stress lowers the threshold for psychosis in someone whose dopaminergic system is already vulnerable.
A critical clinical point is the time criterion. PPDGJ-III mandates that the transition from a nonpsychotic state to a clearly psychotic state must occur within two weeks or less. This acute onset is what separates F23 from schizophrenia (which typically has a prodromal period of weeks to months) and from delusional disorder (which develops insidiously). The abruptness of onset is not merely a descriptive feature; it reflects the underlying pathophysiology of a sudden neurochemical event rather than a gradual neurodegenerative process.
02Classification and Clinical Manifestation
2Classification Overview
Acute Polymorphic Psychotic Disorder without Symptoms of Schizophrenia
Core Features
Rapidly changing, variable hallucinations and delusions + emotional turmoil. No single symptom meets criteria for schizophrenia, mania, or depression consistently.
Duration Rule
If it persists and stabilizes into a recognizable syndrome, reclassify accordingly.
Acute Polymorphic Psychotic Disorder with Symptoms of Schizophrenia
Core Features
Same polymorphic picture as F23.0, plus symptoms that meet schizophrenic criteria for most of the time since onset.
Duration Rule
If schizophrenic symptoms persist > 1 month, reclassify as Schizophrenia (F20.-).
Acute Schizophrenia-like Psychotic Disorder
Core Features
Acute onset + symptoms meeting schizophrenic criteria for most of the time. The polymorphic pattern of F23.0 is not present.
Duration Rule
If schizophrenic symptoms persist > 1 month, reclassify as Schizophrenia (F20.-).
Other Acute Psychotic Disorder Predominantly with Delusions
Core Features
Acute onset + delusions and hallucinations present for most of the time. Criteria for neither schizophrenia nor polymorphic psychosis are met.
Duration Rule
If delusions persist > 3 months, reclassify as Persistent Delusional Disorder (F22.-). If only hallucinations persist > 3 months, reclassify as Other Nonorganic Psychotic Disorder (F28).
Other Acute and Transient Psychotic Disorders
Core Features
Acute psychotic disorders that do not fit any of the above subcategories within F23.
Duration Rule
—
Acute and Transient Psychotic Disorder, Unspecified
Core Features
Used when information is insufficient to classify into a more precise subcategory.
Duration Rule
—
Diagnosis | Core Features | Duration Rule |
|---|---|---|
Acute Polymorphic Psychotic Disorder without Symptoms of Schizophrenia | Rapidly changing, variable hallucinations and delusions + emotional turmoil. No single symptom meets criteria for schizophrenia, mania, or depression consistently. | If it persists and stabilizes into a recognizable syndrome, reclassify accordingly. |
Acute Polymorphic Psychotic Disorder with Symptoms of Schizophrenia | Same polymorphic picture as F23.0, plus symptoms that meet schizophrenic criteria for most of the time since onset. | If schizophrenic symptoms persist > 1 month, reclassify as Schizophrenia (F20.-). |
Acute Schizophrenia-like Psychotic Disorder | Acute onset + symptoms meeting schizophrenic criteria for most of the time. The polymorphic pattern of F23.0 is not present. | If schizophrenic symptoms persist > 1 month, reclassify as Schizophrenia (F20.-). |
Other Acute Psychotic Disorder Predominantly with Delusions | Acute onset + delusions and hallucinations present for most of the time. Criteria for neither schizophrenia nor polymorphic psychosis are met. | If delusions persist > 3 months, reclassify as Persistent Delusional Disorder (F22.-). If only hallucinations persist > 3 months, reclassify as Other Nonorganic Psychotic Disorder (F28). |
Other Acute and Transient Psychotic Disorders | Acute psychotic disorders that do not fit any of the above subcategories within F23. | — |
Acute and Transient Psychotic Disorder, Unspecified | Used when information is insufficient to classify into a more precise subcategory. | — |
Diagnostic Criteria Detail by Subtype
Acute Polymorphic Psychotic Disorder without Symptoms of Schizophrenia
All four criteria (a–d) must be met:
Criterion | Requirement |
|---|---|
(a) Acute onset | Transition from nonpsychotic to clearly psychotic state within 2 weeks or less |
(b) Polymorphic hallucinations/delusions | Several types of hallucinations or delusions, changing in type and intensity from day to day or even within the same day |
(c) Emotional variability | A similarly varied emotional state (emotional turmoil with rapidly shifting affect) |
(d) Exclusion of stable syndromes | Despite the variety, no single symptom is consistently present long enough to meet criteria for schizophrenia (F20.-), manic episode (F30.-), or depressive episode (F32.-) |
The hallmark of F23.0 is instability across all symptom domains. Nothing stays the same. The delusions shift in theme, the hallucinations change modality, and the emotional state is in constant flux. This is the "kaleidoscope" presentation.
Acute Polymorphic Psychotic Disorder with Symptoms of Schizophrenia
Criterion | Requirement |
|---|---|
Meets criteria (a), (b), (c) of F23.0 | The polymorphic, rapidly shifting pattern is present |
Additional: Schizophrenic symptoms | Symptoms fulfilling the diagnostic criteria for schizophrenia (F20.-) must have been present for most of the time since onset of the psychotic picture |
Duration rule | If schizophrenic symptoms persist for more than 1 month, the diagnosis must be changed to schizophrenia (F20.-) |
This subtype is essentially F23.0 plus a recognizable schizophrenic core emerging within the polymorphic storm. Think of it as a polymorphic psychosis in which schizophrenic features are becoming visible but have not yet solidified.
Acute Schizophrenia-like Psychotic Disorder
Criterion | Requirement |
|---|---|
(a) Acute onset | Psychotic symptoms emerge within 2 weeks or less |
(b) Schizophrenic symptoms | Symptoms meeting criteria for schizophrenia (F20.-) must be present for most of the time since the clinical picture became clearly psychotic |
(c) Polymorphic criteria NOT met | The shifting, kaleidoscopic pattern of F23.0 is absent |
Duration rule | If symptoms persist for more than 1 month, reclassify as schizophrenia (F20.-) |
This is the subtype that looks like schizophrenia from the start, but the onset is too abrupt for typical schizophrenia. The key exam point: if you see a schizophrenia-like picture with an onset of less than two weeks and no prodrome, think F23.2 first, not schizophrenia.
Other Acute Psychotic Disorder Predominantly with Delusions
Criterion | Requirement |
|---|---|
(a) Acute onset | Within 2 weeks or less |
(b) Delusions + hallucinations | Must be present for most of the time since onset |
(c) Exclusion | Neither criteria for schizophrenia (F20.-) nor for acute polymorphic psychosis (F23.0) are met |
Duration rule (delusions) | If delusions persist > 3 months, reclassify as Persistent Delusional Disorder (F22.-) |
Duration rule (hallucinations) | If only hallucinations persist > 3 months, reclassify as Other Nonorganic Psychotic Disorder (F28) |
Note the different duration thresholds: 3 months for F23.3 (compared to 1 month for F23.1 and F23.2). This reflects the clinical reality that isolated delusional states can be more protracted without necessarily indicating schizophrenia.
03Diagnostic Workup
Clinical interview (PPDGJ-III criteria)
Purpose
Establish acute onset, symptom pattern, duration, and exclusion of other F-codes
Role
The primary diagnostic method
Collateral history
Purpose
Confirm timeline of onset, premorbid functioning, psychosocial stressors
Role
Essential for establishing the 2-week onset window
Complete blood count, metabolic panel
Purpose
Exclude infection, metabolic derangement (hyponatremia, hypoglycemia, hepatic encephalopathy)
Role
Exclusion of organic cause
Thyroid function tests
Purpose
Exclude hyperthyroidism or thyroid storm (can mimic acute psychosis with agitation)
Role
Exclusion of organic cause
Urine toxicology screen
Purpose
Exclude substance-induced psychosis (amphetamines, cannabis, cocaine, hallucinogens)
Role
Critical differentiator
Blood alcohol level
Purpose
Exclude alcohol intoxication or withdrawal psychosis
Role
Exclusion of organic cause
HIV and syphilis serology
Purpose
Exclude CNS infection (neurosyphilis, HIV encephalopathy)
Role
Exclusion of organic cause
Brain CT or MRI
Purpose
Exclude space-occupying lesion, encephalitis, cerebrovascular event
Role
Exclusion of organic cause
EEG (if indicated)
Purpose
Exclude temporal lobe epilepsy, nonconvulsive status epilepticus
Role
Considered when there is altered consciousness or atypical features
Lumbar puncture (if indicated)
Purpose
Exclude meningitis, encephalitis, autoimmune encephalitis
Role
When infection or autoimmune etiology is suspected
Test | Purpose | Role |
|---|---|---|
Clinical interview (PPDGJ-III criteria) | Establish acute onset, symptom pattern, duration, and exclusion of other F-codes | The primary diagnostic method |
Collateral history | Confirm timeline of onset, premorbid functioning, psychosocial stressors | Essential for establishing the 2-week onset window |
Complete blood count, metabolic panel | Exclude infection, metabolic derangement (hyponatremia, hypoglycemia, hepatic encephalopathy) | Exclusion of organic cause |
Thyroid function tests | Exclude hyperthyroidism or thyroid storm (can mimic acute psychosis with agitation) | Exclusion of organic cause |
Urine toxicology screen | Exclude substance-induced psychosis (amphetamines, cannabis, cocaine, hallucinogens) | Critical differentiator |
Blood alcohol level | Exclude alcohol intoxication or withdrawal psychosis | Exclusion of organic cause |
HIV and syphilis serology | Exclude CNS infection (neurosyphilis, HIV encephalopathy) | Exclusion of organic cause |
Brain CT or MRI | Exclude space-occupying lesion, encephalitis, cerebrovascular event | Exclusion of organic cause |
EEG (if indicated) | Exclude temporal lobe epilepsy, nonconvulsive status epilepticus | Considered when there is altered consciousness or atypical features |
Lumbar puncture (if indicated) | Exclude meningitis, encephalitis, autoimmune encephalitis | When infection or autoimmune etiology is suspected |
The diagnosis of F23 is fundamentally clinical and criterion-based. There is no laboratory test or imaging study that confirms the diagnosis. Instead, all investigations serve to exclude organic and substance-induced causes of acute psychosis.
Step 1: Establish the timeline. The single most important diagnostic act is obtaining a reliable history of when the patient was last functioning normally. A collateral source (family member, coworker) is almost always needed because the patient is typically too disorganized to provide an accurate timeline. The transition from well to psychotic must have occurred within two weeks or less. If the history reveals a gradual prodrome over months, F23 is excluded.
Step 2: Rule out substances. A urine drug screen is non-negotiable. Amphetamine-induced psychosis is the most common mimic of acute polymorphic psychosis: it produces rapidly shifting paranoid delusions, visual and auditory hallucinations, emotional lability, and resolves after the substance is cleared. Without a toxicology screen, you cannot reliably distinguish the two. On an exam, always look for the phrase "urine drug screen was negative" as the green light for diagnosing F23.
Step 3: Rule out organic causes. Basic labs (CBC, metabolic panel, thyroid function) and brain imaging (CT or MRI) are ordered to exclude medical conditions that can present as acute psychosis. Autoimmune encephalitis (especially anti-NMDA receptor encephalitis) is an increasingly recognized cause of acute psychosis in young women and should be considered when the presentation includes seizures, movement disorders, or autonomic instability.
Step 4: Apply PPDGJ-III criteria. Once organic and substance-induced causes are excluded, the clinical picture is matched against the criteria for each F23 subtype. The key decision points are: (1) Is the presentation polymorphic or stable? (2) Are schizophrenic symptoms present? (3) Do delusions predominate?
04Management and Treatment
Acute agitation
Intervention
Benzodiazepines
Details
Lorazepam 1–2 mg IM/IV, may repeat every 4–6 hours. Maximum ~6 mg/day. First-line for acute behavioral control.
Acute psychosis
Intervention
Low-dose antipsychotics
Details
Haloperidol 2–5 mg IM/PO or Risperidone 1–3 mg/day PO. Olanzapine 5–10 mg IM is an alternative.
Maintenance (short-term)
Intervention
Continue antipsychotic at lowest effective dose
Details
Typically for 3–6 months after full symptom resolution, then taper gradually.
Discontinuation
Intervention
Gradual taper
Details
If the patient remains symptom-free for 3–6 months, reduce the dose by 25% every 2–4 weeks. Monitor for relapse during taper.
Psychosocial
Intervention
Psychoeducation + stress management
Details
Educate patient and family about the nature of the illness, warning signs of relapse, and stress-reduction strategies.
If symptoms persist
Intervention
Reclassification
Details
Apply duration rules: >1 month of schizophrenic symptoms changes the diagnosis to schizophrenia; >3 months of delusions changes it to persistent delusional disorder. Adjust long-term management accordingly.
Phase | Intervention | Details |
|---|---|---|
Acute agitation | Benzodiazepines | Lorazepam 1–2 mg IM/IV, may repeat every 4–6 hours. Maximum ~6 mg/day. First-line for acute behavioral control. |
Acute psychosis | Low-dose antipsychotics | Haloperidol 2–5 mg IM/PO or Risperidone 1–3 mg/day PO. Olanzapine 5–10 mg IM is an alternative. |
Maintenance (short-term) | Continue antipsychotic at lowest effective dose | Typically for 3–6 months after full symptom resolution, then taper gradually. |
Discontinuation | Gradual taper | If the patient remains symptom-free for 3–6 months, reduce the dose by 25% every 2–4 weeks. Monitor for relapse during taper. |
Psychosocial | Psychoeducation + stress management | Educate patient and family about the nature of the illness, warning signs of relapse, and stress-reduction strategies. |
If symptoms persist | Reclassification | Apply duration rules: >1 month of schizophrenic symptoms changes the diagnosis to schizophrenia; >3 months of delusions changes it to persistent delusional disorder. Adjust long-term management accordingly. |
Acute stabilization is the first priority. A patient in the throes of an acute polymorphic psychosis can be severely agitated, disoriented, and a danger to themselves or others. Lorazepam (a benzodiazepine) is the safest first-line agent for controlling agitation because it has a rapid onset, does not worsen delirium if the diagnosis turns out to be organic, and has a predictable duration of action. The dose is 1–2 mg given intramuscularly or intravenously, repeated every 4–6 hours as needed.
Once the patient is safe and organic causes have been excluded, a low-dose antipsychotic is started for definitive symptom control. The choice between a first-generation antipsychotic (haloperidol) and a second-generation agent (risperidone, olanzapine) depends on the clinical setting. Haloperidol 2–5 mg IM or PO is widely used in emergency and inpatient settings because of its availability, predictable pharmacokinetics, and low sedation relative to its antipsychotic potency. For patients where extrapyramidal side effects are a concern (particularly young women), risperidone 1–3 mg/day or olanzapine 5–10 mg is preferred.
A common exam pitfall involves the duration of antipsychotic treatment. Because F23 is, by definition, a self-limiting condition, long-term maintenance therapy is not indicated. The standard approach is to continue the antipsychotic at the lowest effective dose for 3 to 6 months after complete symptom resolution, then taper gradually. Abrupt discontinuation risks rebound psychosis. The taper should reduce the dose by approximately 25% every 2 to 4 weeks while monitoring for early signs of relapse.
Electroconvulsive therapy (ECT) is reserved for refractory cases where the patient does not respond to adequate antipsychotic trials, or in situations where medication is contraindicated (such as first-trimester pregnancy with severe psychosis). ECT is highly effective for acute psychotic episodes and should not be overlooked as a treatment option.
The psychosocial component is essential for relapse prevention. The patient and family should receive structured education about the illness, its triggers, and the importance of stress management. Cognitive-behavioral strategies for identifying and managing stressors can reduce the risk of recurrence. Follow-up psychiatric visits should be scheduled at close intervals during the first 6 months after discharge.
The critical "next best step" logic for the exam:
Acutely agitated patient with new-onset psychosis: secure the patient, check vitals, obtain urine drug screen and basic labs.
Organic and substance causes excluded: start low-dose antipsychotic + benzodiazepine for agitation.
Symptoms fully resolved after days to weeks: continue antipsychotic for 3–6 months, then taper.
Symptoms persist beyond the PPDGJ-III duration threshold: reclassify the diagnosis and transition to long-term management appropriate to the new diagnosis.
05Differential Diagnosis and Distractors
Schizophrenia (F20.-)
Why It Is Similar
Shares hallucinations, delusions, and disorganized behavior. F23.2 looks nearly identical to a first episode of schizophrenia.
Key Discriminator
Schizophrenia has a gradual prodrome (social withdrawal, declining function over weeks to months). F23 has onset within 2 weeks with no prodrome. If schizophrenic symptoms in F23 persist > 1 month, reclassify as schizophrenia.
Substance-Induced Psychotic Disorder (F1x.5)
Why It Is Similar
Amphetamine and cannabis-induced psychosis can produce rapidly shifting paranoia, hallucinations, and agitation, mimicking F23.0 perfectly.
Key Discriminator
Positive urine drug screen or history of recent substance use. Symptoms improve with abstinence and supportive care. The vignette will usually include "urine toxicology was negative" to steer you toward F23.
Brief Psychotic Disorder (DSM-5)
Why It Is Similar
Nearly identical concept. Duration is 1 day to 1 month with eventual full return to premorbid function.
Key Discriminator
This is a DSM-5 diagnosis. PPDGJ-III uses ICD-10 criteria (F23). On an exam using PPDGJ-III, use F23 subcategories, not DSM-5 terminology. The two-week onset criterion is the PPDGJ-III hallmark.
Manic Episode with Psychotic Features (F30.2)
Why It Is Similar
Psychotic mania can present with grandiose delusions, agitation, emotional lability, and disorganized behavior.
Key Discriminator
In mania, the elevated or irritable mood is sustained and predominant, and other manic features are present (decreased need for sleep, pressured speech, grandiosity, increased goal-directed activity). In F23.0, the mood is variable and shifting, never sustained in one direction. Criterion (d) of F23.0 explicitly excludes a consistent manic picture.
Persistent Delusional Disorder (F22.-)
Why It Is Similar
Shares prominent delusions. F23.3 can look similar early on.
Key Discriminator
F22 has an insidious onset over months, with stable (non-changing) well-systematized delusions. F23.3 has acute onset within 2 weeks. If delusions in F23.3 persist > 3 months, reclassify as F22.
Delirium (F05.-)
Why It Is Similar
Shares fluctuating consciousness, disorientation, visual hallucinations, and acute onset.
Key Discriminator
Delirium has an identifiable medical cause (infection, metabolic disturbance, medication toxicity), clouding of consciousness with impaired attention, and worsening at night (sundowning). F23 patients are alert and oriented between psychotic episodes.
Acute Stress Reaction / PTSD (F43.-)
Why It Is Similar
Both can follow acute psychosocial stress and present with disorganized behavior and emotional dysregulation.
Key Discriminator
Stress reactions do not include frank psychotic symptoms (true hallucinations, formed delusions). Dissociative symptoms in acute stress reactions may mimic psychosis but lack the characteristic hallucinations and delusions of F23.
Autoimmune Encephalitis (e.g., anti-NMDA receptor)
Why It Is Similar
Acute psychosis in a young woman, often initially diagnosed as a psychiatric disorder.
Key Discriminator
Look for seizures, movement disorders (orofacial dyskinesias), autonomic instability, and progressive deterioration despite antipsychotic treatment. CSF analysis and antibody testing confirm the diagnosis. This is an organic cause that must be excluded before diagnosing F23.
Differential | Why It Is Similar | Key Discriminator |
|---|---|---|
Schizophrenia (F20.-) | Shares hallucinations, delusions, and disorganized behavior. F23.2 looks nearly identical to a first episode of schizophrenia. | Schizophrenia has a gradual prodrome (social withdrawal, declining function over weeks to months). F23 has onset within 2 weeks with no prodrome. If schizophrenic symptoms in F23 persist > 1 month, reclassify as schizophrenia. |
Substance-Induced Psychotic Disorder (F1x.5) | Amphetamine and cannabis-induced psychosis can produce rapidly shifting paranoia, hallucinations, and agitation, mimicking F23.0 perfectly. | Positive urine drug screen or history of recent substance use. Symptoms improve with abstinence and supportive care. The vignette will usually include "urine toxicology was negative" to steer you toward F23. |
Brief Psychotic Disorder (DSM-5) | Nearly identical concept. Duration is 1 day to 1 month with eventual full return to premorbid function. | This is a DSM-5 diagnosis. PPDGJ-III uses ICD-10 criteria (F23). On an exam using PPDGJ-III, use F23 subcategories, not DSM-5 terminology. The two-week onset criterion is the PPDGJ-III hallmark. |
Manic Episode with Psychotic Features (F30.2) | Psychotic mania can present with grandiose delusions, agitation, emotional lability, and disorganized behavior. | In mania, the elevated or irritable mood is sustained and predominant, and other manic features are present (decreased need for sleep, pressured speech, grandiosity, increased goal-directed activity). In F23.0, the mood is variable and shifting, never sustained in one direction. Criterion (d) of F23.0 explicitly excludes a consistent manic picture. |
Persistent Delusional Disorder (F22.-) | Shares prominent delusions. F23.3 can look similar early on. | F22 has an insidious onset over months, with stable (non-changing) well-systematized delusions. F23.3 has acute onset within 2 weeks. If delusions in F23.3 persist > 3 months, reclassify as F22. |
Delirium (F05.-) | Shares fluctuating consciousness, disorientation, visual hallucinations, and acute onset. | Delirium has an identifiable medical cause (infection, metabolic disturbance, medication toxicity), clouding of consciousness with impaired attention, and worsening at night (sundowning). F23 patients are alert and oriented between psychotic episodes. |
Acute Stress Reaction / PTSD (F43.-) | Both can follow acute psychosocial stress and present with disorganized behavior and emotional dysregulation. | Stress reactions do not include frank psychotic symptoms (true hallucinations, formed delusions). Dissociative symptoms in acute stress reactions may mimic psychosis but lack the characteristic hallucinations and delusions of F23. |
Autoimmune Encephalitis (e.g., anti-NMDA receptor) | Acute psychosis in a young woman, often initially diagnosed as a psychiatric disorder. | Look for seizures, movement disorders (orofacial dyskinesias), autonomic instability, and progressive deterioration despite antipsychotic treatment. CSF analysis and antibody testing confirm the diagnosis. This is an organic cause that must be excluded before diagnosing F23. |
06Traps and High-Yield Pearls
The most common way students lose points on questions about F23 involves failing to distinguish between the subtypes based on the PPDGJ-III criteria. Test-writers exploit the fact that students often lump all acute psychoses together. The critical skill being tested is pattern recognition: can you distinguish a polymorphic picture (F23.0/F23.1) from a schizophrenia-like picture (F23.2) from a delusion-predominant picture (F23.3)?
Here is the decision algorithm to internalize:
First, confirm acute onset (within 2 weeks). If the onset is gradual, F23 is off the table.
Second, ask: Is the symptom picture polymorphic (rapidly shifting)?
Yes, and no schizophrenic symptoms: F23.0
Yes, with schizophrenic symptoms: F23.1
Third, if not polymorphic, ask: Are schizophrenic symptoms present?
Yes: F23.2
Fourth, if no schizophrenic symptoms and no polymorphic pattern, ask: Do delusions predominate?
Yes: F23.3
Another common trap is the duration rule. Students forget that F23 is inherently a provisional diagnosis. PPDGJ-III builds in mandatory reclassification thresholds:
Schizophrenic symptoms > 1 month = reclassify as Schizophrenia (F20.-)
Delusions > 3 months = reclassify as Persistent Delusional Disorder (F22.-)
Hallucinations alone > 3 months = reclassify as Other Nonorganic Psychotic Disorder (F28)
A vignette that describes a patient initially diagnosed with F23.1 whose symptoms have persisted for 6 weeks is testing whether you know to change the diagnosis to schizophrenia.
The substance-induced psychosis trap is equally common. If the vignette does not explicitly state that the urine drug screen is negative, be very cautious about diagnosing F23. Test-writers will sometimes describe a classic polymorphic psychosis but hide a line about recent amphetamine use in the social history. Always scan the vignette for substance use before committing to F23.
Finally, remember that F23 carries a favorable prognosis. If the question asks about expected outcome, the answer is full recovery within weeks to months. This is the defining feature that separates F23 from schizophrenia, where the prognosis involves chronic relapsing illness with progressive functional decline.