Patients with and without intellectual disability seeking outpatient psychiatric services: diagnoses and prescribing pattern.

BACKGROUND: The present study examined the presenting problem of psychiatric outpatients, and resulting diagnostic and prescribing patterns, comparing patients with intellectual disability (ID) with non-ID (N-ID) patients seen in the same clinic.
METHODS: This study was a retrospective medical chart review of information in the first psychiatric diagnostic evaluation for the most recent 100 adult patients with mild ID, 100 patients with moderate, severe or profound ID, and 100 matching N-ID patients.
RESULTS: There were significant differences in rates of medical illness, disabilities, history of marriage, children, independent living, and family history of psychiatric and neurological disorders. Individuals with ID were more likely to present with aggression, self-injurious behaviour or physical complaints, whereas N-ID subjects presented more frequently with depression and anxiety complaints. For all groups, depressive disorders were the most frequent class of diagnoses. For those with ID, antipsychotics were used in 32% of subjects, with mood stabilizers in 28% and antidepressants in 27%. The N-ID subjects were most frequently prescribed antidepressants (40%) and anxiolytics (22%). Polypharmacy did not differ significantly among groups.
CONCLUSIONS: Psychiatric practitioners relied on the diagnostic examination to formulate their diagnosis, whereas the chief complaint reflected the view of caregivers of the subjects with ID. In contrast to previous studies, outpatient providers frequently diagnosed depression, and the prescribing pattern showed increased usage of antidepressants and mood stabilizers.