Dexamethasone suppression test in mentally handicapped subjects

Abstract

AbstractObjective:This study investigated the frequency of abnormal Dexamethasone Suppression Test (DST) in a randomly selected group of mentally handicapped subjects.Method:Forty three subjects living in the community were selected and assessed on a variety of clinical rating scales including Hamilton Rating Scale for Depression (HDS) and Wessex Case Register Form (WCRF). DST was conducted on all the patients and the findings correlated with demographic and clinical variables. Groups defined by DST status were also compared using t-test. In subjects who showed an abnormal response, clinical assessments and DST was repeated after 3 months.Results:Only 7 of 43 subjects showed an abnormal response which did not correlate with either the severity of affective symptoms or the presence or absence of behavioural difficulties. Six of the 7 DST positive subjects were either severely or profoundly impaired on DSM-III criteria indicating that the underlying brain pathology may be pathogenetically important. This was supported by the observation that abnormal DST response was enduring at follow up.Conclusions:The findings suggest that DST may be of little value as a diagnostic tool in the mentally handicapped.