Time course for memory dysfunction in early-life and late-life major depression: A longitudinal study from the Juntendo university mood disorder project

Background: Previous studies have demonstrated that patients with depression also have memory dysfunctions during depressive episodes. These dysfunctions partially remain immediately after remission from a depressive state; however, it is unclear whether these residual memory dysfunctions may disappear through long-term remission from depression. The present study compared patients during early-life (age < 60) and late-life (age60) depression while in their remitted stage with healthy controls to elucidate the impact of a long-term course on memory. Methods: Logical memory from the Wechsler Memory Scale-Revised was administered to 67 patients with major depressive disorder (MDD) (47 patients with early-life depression and residual 20 patients with late-life depression) and 50 healthy controls. MDD patients received memory assessments at the time of their initial remission and at a follow-up three years after remission. Results: At the time of initial remission, scores for logical memory were significantly lower in both patient groups compared to matched controls. At follow-up, memory dysfunction for early-life MDD patients disappeared, whereas scores in the late-life MDD group remained significantly lower than those of matched controls. Limitations: All patients in the present study were on antidepressant medications. Conclusions: Our findings suggested that the progress of memory performance in late-life MDD patients may be different from early-life MDD patients.