A Novel Experimental Method for Examining Response to Neurocognitive Challenge in Depression

Abstract

Background: Neurocognitive impairment is a core feature of depression and a robust predictor of everyday functioning. Impairments in psychomotor speed, memory, attention, and executive functioning in depression have regularly been identified throughout the literature. However, knowledge of the contextual factors which may elicit neurocognitive impairment in depression is lacking. Depressotypic thinking, including negatively biased information processing and automatic thought content, has been theorized to impede neurocognitive functioning. This research explored the possibility that neurocognitive load and the perception of neurocognitive challenge are particularly salient contextual features of a task which may elicit depressotypic interference during task completion. In this study, I examined how individuals with depression respond to the initial level of neurocognitive load presented within a task and the subsequent effect on objective and subjective task performance. Method: Individuals with depression (n =20) and age- and sex-matched controls (n = 20) were randomly assigned to complete the n-back task in order of increasing difficulty (i.e., 1-, 2-, and then 3-back) or in order of decreasing difficulty (i.e., 3-, 2-, and then 1-back). Given that it is centrally located between the extremes of highest and lowest neurocognitive challenge, I examined differences in objective performance accuracy and estimates of perceived performance accuracy on the 2-back specifically. Results: I did not find statistically significant support for the hypothesis that individuals with depression within the decreasing neurocognitive load condition would demonstrate the poorest performance accuracy. Additionally, I did not find significant evidence for the hypothesis that individuals with depression who completed the most challenging level first would demonstrate uniquely poor estimates of their performance accuracy. Conclusion: This research highlighted the complexity of measuring neurocognition in depression and the utility of designing alternative measurement approaches. The interaction between features of the depressed mood and neurocognitive performance continues to be an area requiring attention within the literature.