Delusional disorder
Delusional disorder is a primary psychotic illness defined by one or more non-bizarre, fixed delusions lasting at least 1 month, without meeting criteria for schizophrenia and with functioning preserved outside the delusional theme. Diagnosis is clinical after a substance or medical cause is excluded. Management leads with psychotherapy, since antipsychotics are not effective for the core delusion, reserving a low-dose second-generation antipsychotic such as risperidone for overt psychosis or agitation.
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What this article covers
- Overview
Definition: delusional disorder is a primary psychotic illness defined by one or more non-bizarre, fixed, false delusions persisting for at least 1 month, without meeting criteria for schizophrenia and without a significant mood component.
- Epidemiology
Position among the psychotic disorders: grouped with schizophrenia, schizophreniform disorder, and brief psychotic disorder, but separated from them chiefly by the count and duration of symptoms…
- Risk factors
Close relational exposure to an already-delusional individual: cohabiting with, or being emotionally close to, a person who holds a fixed delusion is the specific driver of the shared, induced form…
- Pathophysiology
An isolated, encapsulated delusional system: unlike schizophrenia's broader disturbance across thought process, perception, and negative-symptom domains, delusional disorder involves a single…
- Clinical features
Duration and count threshold: 1 or more delusions present for 1 month or longer is the entry criterion.
- Differential diagnosis
Schizophrenia: 2 or more of delusions, hallucinations, disorganized speech, disorganized/catatonic behavior, or negative symptoms for a significant part of 1 month with dysfunction persisting 6…
- Diagnosis
The diagnosis is clinical, not confirmed by a single test: made when 1 or more non-bizarre delusions have been present for at least 1 month, criteria for schizophrenia are not met, a significant mood…
- Management
If danger to self or others, or severe acute agitation, is present, stabilize first: admit for safety if the risk persists.
- Complications
Impaired decision-making capacity: delusions are a common cause of impaired capacity to consent to evaluation or treatment, reassessed once the delusion is addressed rather than treated as permanent.
- Prognosis
Often a chronic, longstanding course: typically recognized after a history of symptoms spanning many years with no impairment of baseline functioning, not a single acute, remitting episode.
- Prevention
Identify and treat a reversible driver before it becomes fixed: adjust antiparkinsonian dosing in Parkinson disease-associated psychosis, or address another contributing substance or medical…
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