Delusional disorder is a mental disorder characterized by the presence of one or more delusions that persist for at least 1 month. A diagnosis of delusional disorder is not given if an individual has ever had symptoms that meet criteria for schizophrenia. Apart from the direct impact of the delusions, impairments in psychosocial functioning may be minor compared to those seen in other psychotic disorders such as schizophrenia.
The presence of at least 1
delusion with a duration of at least 1
month.
Criterion A
for schizophrenia has never been met.
Apart from the impact of the delusion(s) or its ramifications, functioning is not markedly impaired, and behaviour is not obviously bizarre or odd.
If manic or major depressive episodes have occurred, these have been brief relative to the duration of the delusional periods.
The disturbance is not attributable to the physiological effects of a substance or an other medical condition and is not better explained by another mental disorder, such as body dysmorphic disorder or obsessive-compulsive disorder.
Specify whether:
Specify current severity:
7
days) on a 5-point scale ranging from 0 (not present) to 4 (present and severe)Delusional disorder is highly resistant to treatment with medication alone.[6]
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 |