Delusional Disorder

One or more delusions lasting ≥1 month without other prominent psychotic features.

Etiology (Biopsychosocial Model)

Biological: Dopaminergic dysregulation; possible shared genetic vulnerability with schizophrenia.

Psychological: Cognitive bias, rigid belief systems.

Social: Isolation, immigration stress, cultural misinterpretations.

Symptoms & Diagnosis (Mnemonic: BELIEVE)

  • B - Behavior is not obviously bizarre
  • E - Excludes schizophrenia criteria
  • L - Lasts ≥1 month
  • I - Impact on functioning is limited
  • E - Excludes substance/medical cause
  • V - Various subtypes (e.g., persecutory, erotomanic, somatic)
  • E - Episodes of mood disturbance brief relative to delusional periods

Treatment

Antipsychotics: (e.g., risperidone, olanzapine)

CBT: for cognitive restructuring

Psychoeducation and family involvement

Info

DSM-5-TR Code

F22

Prevalence

~0.2% lifetime prevalence; onset usually in middle to late adulthood.