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

BackgroundPrevious 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 (age≥60) depression while in their remitted stage with healthy controls to elucidate the impact of a long-term course on memory.MethodsLogical 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.ResultsAt 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.LimitationsAll patients in the present study were on antidepressant medications.ConclusionsOur findings suggested that the progress of memory performance in late-life MDD patients may be different from early-life MDD patients.