Systematic Review and Meta-Analysis of the Association Between Subjective and Objective Cognitive Function in Mood Disorders

Abstract

Introduction: The association between subjective and objective cognitive function in mood disorders is hotly debated, particularly in the choice of outcomes to measure pro-cognitive effects of interventions. We systematically reviewed the evidence regarding this association, including analysis of predicting or moderating factors. Methods: We searched Ovid MEDLINE, EMBASE, PsycINFO, and Cochrane Library for studies examining subjective and objective cognitive function in mood disorders (from inception to July 2024). Studies using correlational analyses to examine the association between subjective and objective cognitive function were included in the meta-analysis. Results: Fifty-five studies (59 publications) were identified (n = 5798), with 35 studies included in the meta-analysis. There were weak but statistically significant positive correlations between subjective and objective cognition in all domains except sustained attention, which was at a trend level (p = 0.05). Mood state or mood disorder diagnosis did not impact these correlations. No subjective measure was more highly associated with objective cognitive function than others. Our narrative review of the remaining 20 studies (that did not examine subjective-objective correlations) demonstrated a shift towards calculation of a discrepancy or sensitivity score, rather than simply correlating measures. Conclusion: This is the first systematic review and meta-analysis examining the association between subjective and objective cognition in mood disorders. Our results support the general consensus that there is not a strong relationship. This may relate to the limited ecological validity of objective cognitive tests and highlights the need for assessment of both subjective and objective cognitive function to adequately capture patients' cognitive status.