A descriptive case-register study of delusional disorder.

OBJECTIVE: A few empirically based studies' data on delusional disorder (DD) exist. We aim to describe sociodemographic and clinical correlates of DD and to identify clinical profiles associated to DD and its subtypes.

METHODS: This is a case-register study based on all those subjects attending community mental health services within a geographically well-defined area. Four hundred and sixty-seven patients had been diagnosed as DD cases at psychiatric services serving a catchment area of some 607,494 inhabitants living in South Barcelona (Spain) during a three-year period (2001-2003). A thorough systematic review of computerised medical records was used to establish DSM-IV diagnosis, rendering a valid sample of 370 patients who fulfilled DSM-IV criteria for DD. Independent variables gathered include sociodemographic data, family and personal psychiatric history, and comorbid diagnoses on all DSM-IV axes (including GAF). We used descriptive and univariate statistical methods to explore sample frequencies and correlates across DD types.

RESULTS: The mean age of the patients was 55 years and the sample had a mean GAF score of 51 suggesting a poor functionality; 56.5% of the patients were female. The most frequent DD types were persecutory (48%), jealous (11%), mixed (11%) and somatic (5%), whilst 23% qualified for the NOS type. Most frequent symptoms identified were self-reference (40%), irritability (30%), depressive mood (20%) and aggressiveness (15%). Hallucinations were present in 16% of the patients (6% tactile; 4% olfactory). Nearly 9% had a family history of schizophrenia (higher among those with the jealous subtype) and 42% had a comorbid axis II diagnosis (mostly paranoid personality disorder). Depression was significantly more frequent among the persecutory and jealous types. Finally, global functioning was significantly better among jealous and mixed types and worse amongst erotomanic and grandiose cases (p=0.008).

CONCLUSIONS: In the absence of other similar empirical data, this modest study provides unique empirical evidence of some clinical and risk correlates of DD and its subtypes.