Neurocognitive deficits were only weakly associated with standard depression symptom ratings, and not captured by self-report ratings of cognitive complaint, according to a recent study. Neurocognitive deficits appear to be a separate symptom dimension that cannot be inferred from overall depression severity. Neuropsychological performance was assessed via 10 tasks in a sample of 262 unmedicated patients with major depressive disorder (MDD) and compared to that in healthy volunteers (n=140), then correlated with:

1. standard measures of depression severity including the Hamilton Depression Rating Scale and Beck Depression Inventory,
2. previously established, factor-analytically derived symptom factors that characterize the heterogeneity of these scales, and
3. a separate measure of cognitive complaint (Cognitive Failures Questionnaire) that was included to address the absence of specific questions about cognition in standard rating scales.

Researchers found that neurocognitive performance in these unmedicated MDD patients was not significantly associated with either total scores on the depression severity measures, any of their derived symptom factors, or the degree of subjective cognitive complaint, which itself was most strongly associated with mood disturbance.