Delusional Disorder

Posted byRatel Health
Evidence-based mental health content, reviewed by psychologists and psychiatrists
Attention-Deficit/Hyperactivity Disorder (ADHD)Autism Spectrum DisorderBipolar I DisorderObsessive-Compulsive DisorderPost-Traumatic Stress Disorder

Delusional Disorder

Medically reviewed · Ratel Health editorial team · Sunday, 16 August 2026

A psychotic disorder involving one or more fixed, false beliefs (delusions) lasting a month or longer, without other prominent psychotic symptoms.

Overview

Delusional disorder involves the presence of one or more delusions lasting a month or longer, without the prominent hallucinations, disorganized speech, or significant functional decline typically seen in schizophrenia.

Signs and Symptoms

Symptoms center on fixed, false beliefs that persist despite evidence to the contrary, while functioning outside the area affected by the delusion may remain relatively intact. Experiencing one or more of these symptoms does not necessarily mean that a person has this condition. Diagnosis requires an appropriate clinical evaluation.

Causes and Risk Factors

The exact cause is not fully understood. Genetic factors and certain personality or sensory factors are associated with delusional disorder.

Diagnosis

A diagnosis should be made by a qualified healthcare professional following a comprehensive clinical assessment. Clinicians may use established diagnostic frameworks such as DSM-5-TR and/or ICD-11 as part of a comprehensive assessment.

Treatment

Treatment depends on the individual’s symptoms, clinical history, severity, age, co-occurring conditions, and other relevant factors.

Psychotherapy

Supportive psychotherapy and building a trusting therapeutic relationship can help support engagement in care.

Medication

Antipsychotic medication may be considered, though response can vary between individuals. Medication decisions should be made with a qualified prescribing healthcare professional. Do not start, stop, or change a prescribed medication based solely on information on this page.

Living With Delusional Disorder

Consistent follow-up care and addressing related distress or impairment can support functioning.

When to Seek Professional Help

Professional evaluation may be appropriate if symptoms persist, worsen, cause significant distress, or interfere with work, school, or relationships.

Emergency Situations

If a person may be in immediate danger, is experiencing a medical or psychiatric emergency, or may harm themselves or another person, seek immediate assistance through appropriate local emergency services.

Outlook

The course can be chronic for some individuals, while others experience periods of remission, particularly with sustained treatment engagement.

Related Conditions

Schizophrenia

A chronic psychotic disorder involving disruptions in thinking, perception, and behavior, including hallucinations, delusions, and disorganized thinking.

Shared Psychotic Disorder (Folie à Deux)

A rare condition in which delusional beliefs are transferred from one individual with a primary psychotic disorder to another closely associated person.

Medical Information Disclaimer

Ratel Health provides general educational information and does not provide medical diagnosis, treatment, or individualized medical advice. Information on this page is not a substitute for evaluation or care from a qualified healthcare professional. Do not use this information to diagnose yourself or another person, or to start, stop, or change treatment or medication without consulting an appropriately qualified healthcare professional.

References

  • American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR).
  • National Institute of Mental Health.
  • U.S. Food and Drug Administration.
  • World Health Organization. International Classification of Diseases, 11th Revision.