Epidemiology and demographics

The incidence of delusional disorders is approximately 0.7 to 3.0 cases per 100, 000 individuals annually. The prevalence of delusional disorders is approximately 24 to 30 cases per 100, 000 individuals annually.

Delusional disorder accounts for approximately 1-2% of admissions to inpatient mental health facilities. The incidence of first admissions for delusional disorder is approximately 0.001-0.003%. The lifetime morbid risk of delusional disorder has been estimated to range from 0.05 to 0.1 percent. According to DSM-5, the estimated lifetime prevalence of delusional disorder is 0.2 percent, which is far lower than the estimated lifetime prevalence for other major psychotic disorders such as schizophrenia and bipolar I disorder with lifetime prevalence of 0.3 to 0.87 percent and 0.24 to 0.6 percent respectively. Approximate rates of delusional disorder reported in samples of patients receiving mental health treatment have ranged from 0.5 to 1.2 percent. As the majority of people with delusional disorder do not regard it as an illness or receive treatment, studies likely underestimate the prevalence of the disorder. Delusional disorders are uncommon in psychiatric practice, though this may be an underestimation due to the fact that those afflicted lack insight and thus avoid psychiatric assessment.

The incidence of delusional disorders is approximately 0.7 to 3.0 cases per 100, 000 individuals annually.

The prevalence of delusional disorders is approximately 24 to 30 cases per 100, 000 individuals annually.

Females are more commonly affected with delusional disorder than males.

Delusional disorder commonly affects individuals in middle to late adult life. First admissions to hospital for delusional disorder occur between age 33 and 55 years of age.