The dexamethasone suppression test as a predictor of suicidal behavior in unipolar depression

Abstract

Background Non-suppression on the dexamethasone suppression test (DST) in unipolar depression has been found to be associated with completed suicide, with less consistent data for attempted suicide and hospitalizations for suicidality. The purpose of this study was to examine DST non-suppression as a predictor of these three aspects of suicidal behavior.Methods Records were reviewed for 101 patients who met criteria for major depressive disorder and/or dysthymic disorder and had a DST performed. All patients were treated naturalistically and were followed for an average of 2 years. DST suppressors and non-suppressors were compared with respect to three outcomes: (1) completed suicide; (2) attempted suicide; and (3) hospitalizations for suicidality.Results DST non-suppressors were significantly more likely to have completed suicide or be hospitalized for suicidality than DST suppressors, with a non-significant trend for attempts. Total suicidal events were also significantly more frequent in the non-suppressor group.Limitations Axis II diagnoses and severity of illness were not assessed. Knowledge of DST results may have influenced the decision to hospitalize patients.Conclusions DST non-suppression identifies unipolar depressed patients with a higher risk for future suicide completion or hospitalization for suicidality. Performance of DST upon initiation of treatment may be a useful adjunct in identifying suicidal risk.