Brief psychotic disorder is the diagnosis for psychotic symptoms lasting at least 1 day but less than 1 month, with full return to baseline functioning. The temporal limits are diagnostically definitive — psychotic symptoms beyond 1 month transition to schizophreniform disorder (1-6 months) or schizophrenia (>6 months).
DSM-5 subtypes: with marked stressor (preceded by significant stressor — bereavement, traumatic event, severe life change), without marked stressor, with postpartum onset. The postpartum subtype is a particular pattern with high recurrence risk in future pregnancies.
Typical presentation: rapid-onset psychotic symptoms over hours to days, often with prominent affective features (mood lability), often with clear precipitant or postpartum context. Symptoms typically resolve over 1-4 weeks with treatment. Patient returns to premorbid baseline.
Prognosis is variable. Roughly 50% of patients remain stable long-term without further psychotic episodes — the disorder was a true brief reaction. Roughly 50% develop more chronic psychotic illness (schizophrenia, schizoaffective disorder, bipolar with psychotic features). The variability makes follow-up essential.
Treatment of the acute episode: brief antipsychotic therapy (typically 4-6 months), monitoring for recurrence, addressing precipitating stressors, treating comorbid mood and anxiety. Hospitalization often appropriate given acute severity and behavioral risk.
The postpartum subtype deserves special attention. Postpartum psychosis is a psychiatric emergency typically presenting in the first 2 weeks postpartum. Often a first presentation of bipolar disorder. Recurrence risk in subsequent pregnancies is 40-50% — pre-pregnancy mood stabilizer planning is appropriate for any patient with history of postpartum psychosis. Hospitalization, antipsychotic, often lithium or mood stabilizer indefinitely.
Differential considerations: rule out substance-induced psychosis (toxicology), medical/neurologic causes (electrolyte, infection, autoimmune encephalitis, structural lesion), delirium (especially in older patients). Acute psychosis with rapid onset should prompt medical workup before committing to primary psychiatric diagnosis.
When you encounter a patient with first-onset psychosis lasting less than 1 month with clear return to baseline, brief psychotic disorder is the appropriate diagnosis — but the follow-up plan matters. Half will be stable; half will not. Continued monitoring shapes long-term care.