The minimal effect of depression on cognitive functioning when accounting for TOMM performance in a sample of US veterans

While many studies have demonstrated a relationship between depression and cognitive deficits, most have neglected to include measurements of performance validity. This study examined the relationship between depression and cognition after accounting for noncredible performance. Participants were veterans referred for outpatient clinical evaluation. The first set of regression analyses (N = 187) included age, sex, and education in Model 1, Beck Depression Inventory-2 (BDI-2) added in Model 2, and pass/failure of Test of Memory Malingering (TOMM) added in Model 3 as predictors of 12 neuropsychological test indices. The second set of analyses (N = 559) mirrored the first but with Major Depressive Disorder (MDD) diagnosis in Models 2 and 3. In the first analyses, after including TOMM in the model, only the relationship between BDI-2 and verbal fluency remained significant, but this did not survive a Bonferroni correction. In the second analyses, after including TOMM and Bonferroni correction, MDD diagnosis was a significant predictor only for CVLT-II Short Delay Free Recall. Therefore, the relationship between depression and cognition may not be driven by frank cognitive impairment, but rather by psychological mechanisms, which has implications for addressing depressed individuals' concerns about their cognitive functioning and suggest the value of providing psychoeducation and reassurance.