Schizoaffective disorder is a mental disorder characterized by a major mood episode (either manic or depressive) that co-occurs at the same time with symptoms of schizophrenia.
There are limited studies on the prevalence of schizoaffective disorder. It is estimated that 30% of cases occur between the ages of 25 and 35, and it occurs more frequently in women than men.[1][2] There is an estimate lifetime prevalence of 0.3%.[3]
Prognostic studies have been difficult due to the diagnostic challenges associated with schizoaffective disorder. One study found that 50% of cases showed favourable outcomes (i.e. - minimal symptoms, no symptoms, and/or employment).[4]
An uninterrupted period of illness during which there is a major mood episode (depressive or manic) concurrent with Criterion A
of schizophrenia.
Criterion A1
: Depressed mood.
Delusions or hallucinations for at least 2
weeks in the absence of a major mood episode (depressive or manic) during the lifetime duration of the illness.
Symptoms that meet criteria for a major mood episode are present for the majority
of the total duration of the active and residual portions of the illness.
The disturbance is not attributable to the effects of a substance (e.g. - a drug of abuse, a medication) or another medical condition.
2
weeks of psychosis without any mood symptoms, the majority of illness time is dominated by mood symptoms – hence the name schizo (2 weeks
) affective (majority
) disorder.
Specify whether:
Specify if:
The following course specifiers are only to be used after a 1
-year duration of the disorder and if they are not in contradiction to the diagnostic course criteria.
Given its uncertainty as a diagnostic construct, schizoaffective disorder is very poorly researched in terms of understanding pathophysiology.[9] Very old studies from the 1980s suggest there are changes in dopamine, norepinephrine, and serotonin. White matter changes are also thought to be involved.[10]
2
weeks in which there are only psychotic symptoms (delusions and hallucinations) and without mood symptoms. Additionally, a major mood episode (again, either depression or mania) is also present for the majority of the total duration of the illness. Once the psychotic symptoms predominate the majority of the total duration of the illness, the diagnosis would shift towards a diagnosis of schizophrenia. Also remember that schizophrenia requires 6 months of prodromal or residual symptoms, and schizoaffective disorder does not require this criterion.2
weeks of psychotic symptoms (delusions and hallucinations) without mood symptoms. Patients also do not meet Criterion A
of schizoaffective disorder.2
weeks in which there are only psychotic symptoms without mood symptoms. Again, patients also do not meet Criterion A
of schizoaffective disorder.The term psychosis has been defined in various ways in the medical literature over time. The narrowest and current definition of psychosis is hallucinations and delusions, with the lack of reality testing or insight. A broader definition of psychosis would also include disorganized thought, emotions, and behaviour. This loose definition was more common in the past, and schizophrenia was often overdiagnosed as a result.
Type | Onset | Length | Psychotic Symptoms | Mood Symptoms | Functional Decline? |
---|---|---|---|---|---|
Brief psychotic disorder | Sudden | 1 day to 1 month | At least 1 of: • Delusions • Hallucinations • Disorganized speech • Grossly disorganized or catatonic behaviour | No | Full resolution of symptoms |
Schizophreniform disorder | Can be prodromal | 1 month to 6 months | At least 2 of: • Delusions • Hallucinations • Disorganized speech • Grossly disorganized or catatonic behaviour • Negative symptoms | No | Not required |
Schizophrenia | Can be prodromal | > 6 months | At least 2 of: • Delusions • Hallucinations • Disorganized speech • Grossly disorganized or catatonic behaviour • Negative symptoms | No | Required |
Schizoaffective disorder | Can be prodromal | Major mood episode + 2 weeks of isolated psychotic symptoms + predominantly mood symptoms over course of illness | • Delusions or hallucinations for 2 or more weeks, which must be in absence of a major mood episode (depressive or manic) during the lifetime duration of the illness | Required | Not required |
Delusional disorder | Can be prodromal | > 1 month | • One or more delusions, with no other psychotic symptoms. | No | Normal function aside from impact of delusions |
Depending on the patient's presentation, additional investigations may be ordered, including: CBC, lipids, Urine Drug Screen, TSH, infectious causes (HIV/RPR). Neuroimaging is indicated if there are any neurological deficits.