Mental disorders and medical conditions. A community study in a small island in Spain

This study focuses on the comorbidity between medical and psychiatric illnesses in a sample taken from the general population.

We design a two-stage epidemiological community study in the island of Formentera (Spain), using the Schedules for Clinical Assessment in Neuropsychiatry (SCAN). In the first stage, the sample (N=697) was screened using the General Health Questionnaire (GHQ-28). In the second stage, the SCAN, subjects' clinical histories and General Practitioners' diagnosis were used to evaluate psychiatric disorders and medical illnesses. The final sample comprised 242 subjects.

Subjects with diagnosed ICD-10 mental disorders presented higher comorbidity with medical pathologies than the group of respondents without psychiatric diagnosis, although the differences were not statistically significant. Of the psychiatric conditions, mood disorders (in which differences were significant) and neurotic disorders were the ones that most frequently presented comorbidity, followed by sleep disorders. Mean scores on the GHQ-28 used at the screening stage, and mean scores on neurotic, depressive and somatic symptoms on the SCAN, were significantly higher in the comorbid group. Comorbidity was more frequent in females.

More studies on comorbidity in general population are required, with diagnostic instruments that cover the whole of the psychiatric spectrum and correct assessment systems for medical diagnosis.