Depressive symptoms as a risk factor for memory decline in older adults: a longitudinal study using the dual change score model Depression as a risk factor for memory decline in older adults.

Background: the direction of the longitudinal association between depression and memory remains a topic of intense debate. A unidirectional association where depression impacts the change in memory (or vice-versa) and a bidirectional association where the trajectories of both dimensions affect each other lead to different clinical implications. Method: This study aimed to investigate the directionality of the depression-memory association in a sample of 2,057 older adults aged between 60 to 99 years old from the Virginia Cognitive Aging Project (VCAP). We used the bivariate dual change score model to investigate the directionality of the association between episodic memory and three dimensions of depression (somatic, depressed affect, and positive affect) throughout ten years (five measurement points), controlling for age, education, and gender. Results: slight decline is observed for memory and stability for depression over the ages of 60 – 99. All depression scales at a given time-point predicted the subsequent change in memory with a negative association, meaning that higher depression is linked with a steeper decline in memory by the next time-point (γDep = 1.768; SE = 0.566; p < 0.05). The opposite model in which memory predicted depression and the bidirectional model were both much weaker than the depression predicting memory model. Conclusions: Our findings support a unidirectional association with depression preceding an accelerated decline in memory in older adults. We discuss the clinical implications for depression as a risk factor for a subsequent memory decline. notReviewed unknown other other