Chronic and severe depression linked to persistent cognitive dysfunction

Recent study conducted by Matcham and team showed that there is a connection between chronic depression severity and persistent cognitive difficulty. The findings of this study were published in Psychological Medicine.

Working memory, executive function, attention, and processing speed deficiencies are among the cognitive impairments seen in major depressive disorder (MDD), which may be linked to psychomotor slowness, anhedonia, and poor mood. Depression episodes frequently include and are followed by cognitive symptoms. The relationship between self-reported and performance-based cognition and depression and functional outcomes is poorly understood. The purpose of the current study is to characterize how cognitive problems persist in MDD patients and determine whether there is a correlation between subjective and objective measurements of these problems.

A planned naturalistic observational clinical cohort study of 623 people with recurrent major depressive disorder (MDD) is the subject of this secondary analysis. Every 3 months, participants performed cognitive function evaluations based on performance and self-report, as well as validated tests of depression, functional impairment, and self-esteem. The maximum follow-up period for participants was two years. To determine if ongoing cognitive challenges are associated with levels of depression and functional impairment during follow-up, multilevel hierarchically nested modeling was used to analyze between- and within-participant variation across time.

The key findings of this study were:

1. 508 people (81.5%) gave information. Throughout the follow-up, there was a correlation between rising levels of depression and functional impairment and self-reported cognitive problems that persisted.

2. People with high persistence of objective cognitive difficulties (>75% of timepoints) reported substantially greater degrees of depression and functional impairment over time compared to those with modest persistence (25% of timepoints).

3. According to analysis of the individual cognitive modules, executive function impairment is linked to lower functioning and slow processing speed is especially significant for escalating depression symptoms.

Reference:

Matcham, F., Simblett, S. K., Leightley, D., Dalby, M., Siddi, S., Haro, J. M., Lamers, F., Penninx, B. W. H. J., Bruce, S., Nica, R., Zormpas, S., Gilpin, G., Narayan, V. A., Hotopf, M., & Wykes, T. (2022). The association between persistent cognitive difficulties and depression and functional outcomes in people with major depressive disorder. In Psychological Medicine. Cambridge University Press. https://doi.org/10.1017/s0033291722003671