The findings of a study that connected neuroticism to anxiety and anhedonia, 2 features of major depressive disorder (MDD) that are linked to worse treatment outcomes, were published in the Journal of Affective Disorders.
In previous research, neuroticism, understood in this study as a “propensity to experience negative emotions,” has predicted mood and anxiety disorders. The investigators also examined cognitive control and reward learning, both associated with depression, hoping to clarify mechanisms of heterogeneous presentations of MDD.
The researchers used baseline data from 296 racially and socioeconomically diverse patients with early-onset MDD from the Establishing Moderators and Biosignatures of Antidepressant Response in Clinical Care trial, conducting a path analysis to model relationships between anxiety and anhedonia vs neuroticism, cognitive control, and reward learning. Eligible participants scored ≥14 on the Quick Inventory of Depression Symptomatology and were antidepressant-free for ≥3 weeks before assessments.
After recruitment, participants were assessed according to the State-Trait Anxiety Inventory, Snaith-Hamilton Pleasure Scale, NEO Five-Factory Inventory, Eriksen Flanker Task, and the Probabilistic Reward Task.
Analyses demonstrated a positive association between neuroticism and both anhedonia (standardized coefficient=0.26; P <.001) and anxiety (standardized coefficient=0.40; P <.001). The researchers proposed that neurotic traits such as rumination and worry might explain, in part, why neuroticism appears to complicate the treatment of depression.
Reward learning appeared to have no significant relationship to anxiety or anhedonia. Enhanced cognitive control, in contrast, appeared to protect against anxiety (standardized coefficient=−0.18; P <.05).
A limitation of the study was its cross-sectional nature; no causal relationships were established.
Liao A, Walker R, Carmody T, et al. Anxiety and anhedonia in depression: associations with neuroticism and cognitive control. J Affect Disord. 2019;245:1070-1078.