Delusional Disorder

Delusional Disorder

Non-bizarre delusions including feelings of being followed, poisoned, infected, deceived or conspired against, or loved at a distance. Non-bizarre referred to real life situations which could be true, but are not or are greatly exaggerated. Bizarre delusions, which would rule out this disorder, are those such as believing that your stomach is missing or that aliens are seeking you out to be their leader. Delusional disorder can be subtyped into the following categories: erotomanic, grandiose, jealous, persecutory, somatic, and mixed.

Symptoms include

  • Nonbizarre delusions for at least one month.
  • Absence of obviously odd or bizarre behavior.
  • Schizoaffective Disorder and Mood Disorder with Psychotic Features have been ruled out.
  • Absence of evidence that an organic factor initiated and maintained this psychotic disturbance.
  • Absence of prominent hallucinations of a voice for at least one week. Absence of visual hallucinations for at least one week.
  • Has never met the criteria for the active phase of Schizophrenia.


  • Erotomanic Type: Predominately erotomanic delusions.
  • Grandiose Type: Predominately grandiose delusions.
  • Jealous Type: Predominately delusions of jealousy.
  • Persecutory Type: Predominately persecutory delusions.
  • Somatic Type: Predominately somatic delusions.
  • Unspecified Type: Doesn't fit any of the previous categories.

These patients, who tend to be in their 40's, may be may not realise that they have a delusional disorder until it is pointed out by family or friends. Even the diagnosis may be difficult because many do not voluntarily seek treatment. They are frequently hypersensitive and argumentative. Although they may perform well occupationally and in areas distant from their delusions, they tend to be social isolates either by preference or as a result of their interpersonal inhospitality (i.e., spouses frequently abandon them). Social and occupational dysfunction, when it occurs, usually is in direct response to their delusions.

Associated Features

  • Psychosis
  • Depressed Mood
  • Somatic or Sexual Dysfunction
  • Odd or Eccentric or Suspicious Personality

Differential Diagnosis

Some disorders have similar symptoms. The clinician, therefore, in his diagnostic attempt has to differentiate against the following disorders which need to be ruled out to establish a precise diagnosis.

  • Schizophrenia
  • Mood Disorders
  • Psychosis NOS
  • Paranoid Personality Disorder
  • Body Dysmorphic Disorder
  • Parkinson's Disease
  • Huntington's
  • Vitamin Deficiency
  • Delirium
  • Dementia
  • Drug-Induced
  • Endocrinopathies
  • Limbic System Pathology
  • Serious Liver and Kidney disease.


The cause of delusional disorder is not known. Some studies suggest a biological component due to increased prevalence in first degree relatives of individuals with the disorder. There is a tendency for their family relationships to be characterized by turbulence, callousness, and coldness yet the significance of the patter is unclear typical defense mechanisms seen in these patients include denial, projection, and regression.

A delusional disorder appears to run distinct from schizophrenia and mood disorders, and does not appear to be a prodrome to either of these conditions.

Biologic Theories

The relatively common occurrence of delusions in neurological illness has led investigators to speculate on the role of the limbic system, basal ganglia, and neocortical association areas. No good current unifying theory.

Psychodynamic Theories

Use of the defense mechanisms of reaction formation, denial, projection: e.g. paranoia


Hospitalize if patient is a danger to self or others, need a rapid diagnostic work-up. Antipsychotic drugs are the drugs of choice, efficacy is not clear.

Counseling and Psychotherapy




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