Neural signal variability relates to maladaptive rumination in depression

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Science

Background:

• Rumination, a common depression symptom, has maladaptive (brooding) and adaptive (reflection) subtypes.
• Brooding worsens mood, while reflection may reduce depression symptoms.
• Previous research links rumination to prefrontal brain regions and BOLD signal variability to cognitive flexibility.

Purpose of the Study:

• To investigate if rumination subtypes (brooding vs. reflection) are associated with distinct patterns of blood oxygen-level-dependent (BOLD) signal variability in depression.
• To examine the neural circuitry underlying maladaptive rumination in depression.

Main Methods:

• Resting-state functional magnetic resonance imaging (fMRI) data were collected from 79 women with varying depression histories.
• Differences in BOLD signal variability (BOLD_SD) were analyzed in brain regions implicated in rumination, including the dorsolateral prefrontal cortex (dlPFC).

Main Results:

• Greater brooding was associated with lower BOLD_SD in the dlPFC, independent of depression severity.
• Women with current depression showed reduced BOLD_SD in the dlPFC compared to those with no depression history.
• Depression history correlated with BOLD_SD in the dlPFC.

Conclusions:

• This study provides novel evidence linking maladaptive rumination (brooding) to decreased neural signal variability in the dlPFC.
• Reduced prefrontal neural signal variability may be implicated in the pathophysiology of depression.