schizoaffective disorders

**DEFINITION (DSM-5-TR):** An uninterrupted period of illness during which there is a major mood episode (major depressive or manic) concurrent with Criterion A of schizophrenia (delusions, hallucinations, disorganized speech, grossly disorganized/catatonic behavior, negative symptoms; ≥2 required, one must be delusions, hallucinations, or disorganized speech). Key criteria: 1. Delusions or hallucinations for ≥2 weeks in the ABSENCE of a major mood episode (this separates it from mood disorder with psychotic features). 2. Mood episode symptoms are present for the majority of the total duration of the active and residual illness. 3. Not attributable to a substance or another medical condition.

**SUBTYPES:** - Bipolar type: manic episode is part of the presentation (major depressive episodes may also occur). - Depressive type: only major depressive episodes.

**DIFFERENTIAL (high-yield "timing" distinctions):** - Schizophrenia: mood episodes are brief relative to the total psychotic illness; psychosis ≥6 months. - Mood disorder with psychotic features (MDD or bipolar): psychosis occurs ONLY during mood episodes. - Schizoaffective: psychosis ≥2 weeks WITHOUT mood symptoms, but mood symptoms are present most of the illness. - Schizophreniform: schizophrenia symptoms 1–6 months. - Brief psychotic disorder: 1 day to 1 month. - Delusional disorder: non-bizarre delusions ≥1 month, without other schizophrenia symptoms and with relatively preserved functioning. - Also rule out substance-induced psychosis (amphetamines, PCP, steroids), delirium, and medical causes (TLE, SLE, Huntington disease, Wilson disease).

**EPIDEMIOLOGY/ETIOLOGY:** - Lifetime prevalence is about 0.3%, lower than schizophrenia (about 1%). - Women are affected more often than men, with later onset in women. Onset is typically in early adulthood. - Strong genetic overlap with schizophrenia and bipolar disorder (family history of either increases risk). - Likely involves dopamine dysregulation (mesolimbic hyperactivity → positive symptoms) plus mood-circuit dysfunction (serotonin, norepinephrine).

**CLINICAL COURSE/PROGNOSIS:** - Prognosis is intermediate: better than schizophrenia, worse than mood disorders alone. The bipolar type has a better prognosis than the depressive type. - Better prognosis: acute onset, prominent mood symptoms, good premorbid functioning, female sex, identifiable stressor, family history of mood disorder. - Increased suicide risk (about 5–10%, especially in the depressive type), so always assess for suicidality. - Comorbid substance use is common.

**MANAGEMENT:** - Antipsychotic is the cornerstone of treatment. Paliperidone is the only FDA-approved agent (also long-acting injectable for adherence). - Bipolar type: add a mood stabilizer (lithium, valproate). - Depressive type: add an antidepressant (SSRI). - Psychosocial: psychoeducation, CBT, social skills training, supported employment, assertive community treatment. - ECT is useful for refractory or catatonic presentations or severe depression. - Clozapine for treatment-resistant illness or persistent suicidality. - Monitor for metabolic syndrome with second-generation antipsychotics, and for lithium toxicity/renal and thyroid effects.

**BOARD PEARLS:** - Stem clue: a patient with hallucinations/delusions lasting >2 weeks even when mood is normal, plus prominent episodes of mania or depression → schizoaffective. - The question is nearly always testing the timing relationship between mood and psychotic symptoms. - Do not confuse with bipolar I with psychotic features, where psychosis is limited to mood episodes.