Executive dysfunction and long-term outcomes of geriatric depression

Background: This study investigated the relationship of executive and memory impairment to relapse, recurrence, and course of residual depressive symptoms and signs after remission of geriatric major depression. Methods: Fifty-eight elderly subjects remitted from major depression received continuation nortriptyline treatment (plasma levels 60-150 ng/mL) for 16 weeks and then were randomly assigned to either nortriptyline maintenance therapy or placebo for up to 2 years. Diagnosis was made using the Research Diagnostic Criteria and the DSM-IV criteria after an interview using the Schedule for Affective Disorders and Schizophrenia. Executive dysfunction and memory were assessed with the Dementia Rating Scale, disablity and social support were rated with the Philadelphia Multiphasic Instrument, and medical burden was assessed with the Cumulative Illness Rating Scale. Results: Abnormal initiation and perseveration scores, but not memory impairment, were associated with relapse and recurrence of geriatric depression and with fluctuations of depressive symptoms in the whole group and in subjects who never met criteria for relapse or recurrence during the follow-up period. Memory impairment, disability, medical burden, social support, and history of previous episodes did not significantly influence the outcome of depression in this sample. Conclusions: Executive dysfunction was found to be associated with relapse and recurrence of geriatric major depression and with residual depressive symptoms. These observations, if confirmed, will aid clinicians in identifying patients in need of vigilant follow-up. The findings of this study provide the rationale for investigation of the role of specific prefrontal pathways in predisposing or perpetuating depressive syndromes or symptoms in elderly patients.