Association between depression severity and neurocognitive function in major depressive disorder: A review and synthesis.

Abstract

The effects of major depressive disorder (MDD) on neurocognitive function remain poorly understood. Results from published studies vary widely in terms of methodological factors, and very little is known about the effects of depression severity and other clinical characteristics on neurocognitive function. The purpose of this review was to synthesize prior research findings regarding neurocognitive functioning in patients with MDD and varying levels of depression severity and to provide recommendations for future directions. Overall, this review suggests that MDD has been inconsistently associated with neurocognitive functioning and there is limited understanding regarding the relationship between depression severity and neurocognitive sequelae. There was much heterogeneity on depression severity-related factors across studies assessing neurocognitive function in MDD, as well as substantial variability in the consideration of depression severity among studies, which suggests a need to further explore this important issue.

Cognitive function and lifetime features of depression and bipolar disorder in a large population sample: Cross-sectional study of 143,828 UK Biobank participants

“…Cognitive impairment is a common feature of mood disorders, persisting throughout remission or euthymia, 56 and contributing to functional disability (1)(2)(3)(4)(5)(6). Impairment is typically found on tests of attention, working 57 and episodic memory, processing speed and executive function, with standardised effect sizes in the 58 medium range compared to non-mood disordered controls (3)(4)(5)(6).…”

Executive functions in major depressive disorder

“…In contrast, a previous study by Hammar et al, showed poor performance on executive functions in depressed patients in general, but there was no association between the severity of depression and executive functions (8). Thus, the understanding and knowledge regarding the relationship between depression severity and neuro cognitive sequelae appears to be limited and somewhat conflicting (10).…”

“…The severity of depression has been reported to be associated with impaired executive functioning (7). Further studies have examined the relationship between neurocognitive dysfunction and factors such as age, age of onset, duration of illness and number of episodes and results have been equivocal (9)(10)(11). Endogenous (melancholic) depression has been reported to be associated with greater impairment of executive functioning compared to non-endogenous depression (9,12,13).…”

Associations between neurocognitive functioning and social and occupational resilience among South African women exposed to childhood trauma

“…Next, we proceeded with a focused analysis of the significant associations evident in the univariate correlations by conducting a series of hierarchical multivariate regressions. As age, education, and HIV status are known to predict neurocognitive performance (Devlin et al, 2012), as well as depressive symptoms (McClintock, Husain, Greer, & Cullum, 2010) and Posttraumatic Stress Disorder (PTSD; American Psychiatric Association, 2000; Scott et al, 2015), these variables were entered in the first step to capture within-source variability. Then, neuropsychological variables were entered in the second step to measure between-source variability, thereby isolating the variance explained by our neuropsychological variables.…”