Mental Health

Schizoaffective disorder

Schizoaffective disorder is a specialist psychotic disorder in which schizophrenia symptoms and a clinically significant mood episode occur in the same illness; diagnosis depends on the classification system and a reliable time course, so psychosis, mood, risk, medical causes and treatment response must all be assessed longitudinally.

In a nutshell

Schizoaffective disorder combines a primary psychotic syndrome with a significant mood episode, but its diagnostic threshold depends on the classification system: current WHO ICD-11 requires concurrent schizophrenia and moderate or severe mood-episode requirements for at least 1 month, whereas DSM-5 uses a longitudinal 2-week period of psychosis without a major mood episode. In UK practice, diagnosis is specialist and longitudinal. Manage immediate risk, exclude medical and substance causes, treat psychosis with a specialist antipsychotic trial, treat the manic or depressive domain through the relevant NICE pathway, and provide psychological, family, physical-health and relapse care.

Classic presentation

A person has delusions or hallucinations with a clear manic, mixed or severe depressive episode, and a history that does not fit neatly into schizophrenia or psychotic mood disorder. Establish the timeline, assess suicide and disinhibition risk, examine for medical causes and refer for specialist assessment.

Key points

The central problem is the relationship between psychosis and mood symptoms over time; one cross-sectional consultation is rarely enough.
Name the classification system: current WHO ICD-11 requires concurrent schizophrenia and moderate or severe mood-episode criteria for at least 1 month; the familiar 2-week psychosis-without-major-mood-episode criterion is DSM-5.
Psychosis only during a mood episode favours bipolar disorder or depression with psychotic features; persistent psychosis with mood symptoms that are brief or secondary favours schizophrenia.
First-episode or atypical psychosis requires physical, neurological, medication and substance assessment; do not diagnose a primary disorder from symptoms alone.
Use NICE CG178 for psychosis, CG185 for mania or bipolar features and NG222 for psychotic depression; avoid an automatic antipsychotic-plus-mood-stabiliser prescription.
Before antipsychotics record metabolic, cardiovascular, prolactin, movement, nutritional and ECG baselines when indicated; monitor systematically.
Severe risk, catatonia, treatment resistance, poor self-care or inability to protect dependants may require inpatient or specialist complex-psychosis care.

First-line investigation

Specialist longitudinal psychiatric, risk, physical, neurological, medication and substance assessment with collateral information and targeted tests.

Management

Protect life, safety and dependants

Assess suicide, self-harm, violence, command hallucinations, severe self-neglect, mania, catatonia, children and dependants; arrange urgent specialist or emergency assessment and the safest least restrictive setting.^2,7,4
Look for delirium, infection, neurological disease, endocrine or metabolic illness, medication effects and intoxication or withdrawal in parallel with psychiatric care.^2,5

Build the diagnostic timeline

Use specialist assessment, collateral information and previous records to map psychosis, mood episodes, treatment, substances, physical illness and function; state whether the current formulation is based on ICD-11 or another classification.^2,1,3,4

Treat psychosis and the active mood syndrome

Offer a shared specialist antipsychotic therapeutic trial with baseline physical-health checks, target symptoms, expected response and a 4-to-6-week optimum-dose review; use current BNF or product information for the individual medicine.^2,8
For mania or mixed symptoms follow NICE CG185; for psychotic depression use specialist coordinated care and consider combined antidepressant and antipsychotic treatment under NG222. Review for switching, suicidality, interactions and adverse effects.^3,4,8

Restore function and prevent relapse

Offer CBT for psychosis, family intervention, social and occupational rehabilitation, substance-use support and physical-health care; involve carers appropriately and document a crisis and early-warning plan.^2,9,6
Monitor psychosis, mood, suicide risk, adherence, movement effects and metabolic health; review treatment at least annually, consider complex-psychosis or clozapine assessment when indicated, and reduce medication only gradually with specialist relapse monitoring.^2,9,6,8

Exam traps

Do not teach the DSM-5 2-week criterion as if it were the current WHO ICD-11 definition; state the classification.
Psychosis with depression is not automatically schizoaffective disorder: consider psychotic depression and assess whether the psychosis is confined to mood episodes.
Do not start antipsychotics for a first presentation of sustained psychosis in primary care without consultant psychiatrist involvement.
Mania, severe depression, command hallucinations, catatonia, delirium, suicidality or dangerous disinhibition are emergency risk states.
Do not use antidepressant monotherapy in a manic or mixed presentation; review for mood switching and follow NICE CG185.
Clozapine is not a casual next step: confirm adequate antipsychotic trials and obtain specialist psychosis-MDT review.
Do not stop antipsychotics abruptly; use gradual specialist reduction with relapse monitoring and a written crisis plan.

Key sources

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.