Depression and Episodic Memory Across the Adult Lifespan: A Meta-Analytic Review

Public Significance Statement This meta-analysis demonstrated small to moderate depression-related deficits in episodic memory. Deficits were more pronounced in older age, in clinical depression, and in those receiving pharmacological treatment, while fewer deficits were observed in memory for negative material and with higher educational attainment. By shedding light on depression's nuanced relationship with episodic memory, the present work encourages a greater consideration of cognitive symptoms when diagnosing and treating depression. Episodic memory deficits have increasingly been recognized as a cognitive feature of depression. To quantify these deficits and determine how they are moderated by various tasks (e.g., stimulus valence) and participant (e.g., age, depression diagnosis) variables, we conducted a three-level meta-analysis on 995 effect sizes derived from 205 studies with 236 unique comparisons between depressive and control groups on episodic memory measures. Overall, depression was associated with small to moderate deficits in episodic memory, Hedges' g = -0.36, 95% CI [-0.41 to -0.31]. Effects were larger in older age, in diagnosed compared to subthreshold depression, and in those taking medication for depression; effects did not differ between those with current and remitted symptoms. Stimulus valence moderated the effects, such that depression-related deficits were particularly pronounced for positive and neutral stimuli, but not for negative stimuli. Educational attainment served as a sort of protective factor, in that at higher levels of education, depressed group performance was more similar to that of controls. These findings confirm the episodic memory deficits in depression but highlight the important differences in the size of these deficits across a number of task- and participant-related variables.