Schizophrenia spectrum and other psychotic disorders
Delusional Disorder
Delusional disorder involves one or more fixed delusional beliefs lasting at least one month, while the full core picture of schizophrenia has never been present.
Understanding fixed beliefs
Themes may be persecutory, jealous, erotomanic, grandiose, somatic or mixed. A belief may concern something theoretically possible, yet the conclusion and certainty are not supported by the available evidence.
Outside the direct effects of the belief, overall functioning may remain relatively preserved and behaviour need not be markedly disorganised. The diagnosis does not imply violence; risk is assessed individually from behaviour, intent and context.
Careful assessment
- Culture, religion, language and actual lived experience must be considered before a belief is classified as delusional.
- Hallucinations, if present, are not prominent and are related to the delusional theme.
- Clinicians consider mood episodes, substances, medicines, neurological and medical conditions, OCD, BDD and other psychotic disorders.
Treatment
Consistent psychiatric and mental health contact initially focuses on safety, sleep, distress and functioning. Antipsychotic medication may be offered with monitoring and should not be stopped abruptly without medical advice.
CBT for psychosis can explore alternative interpretations and reduce distress or risky responses without humiliating confrontation. Family information can support communication and recognition of warning signs.
When to seek help
Assessment is important when a fixed belief persists, causes fear or conflict, or leads to surveillance, repeated complaints, unnecessary procedures or isolation. Specific threats, stalking, weapon access, suicidal intent, severe confusion or inability to care safely for oneself needs emergency evaluation.