Decreased Resting-State Activity in the Precuneus Is Associated With Depressive Episodes in Recurrent Depression.

OBJECTIVE

To investigate alterations in resting-state spontaneous brain activity in patients with major depressive disorder (MDD) experiencing multiple episodes.

METHODS

Between May 2007 and September 2014, 24 recurrent and 22 remitted patients diagnosed with MDD with the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I), and 69 healthy controls matched for age, sex, and educational level participated in this study. Among them, 1 healthy control was excluded due to excessive head motion. The fractional amplitude of low-frequency fluctuation (fALFF) was assessed for all recruited subjects during the completion of resting-state functional magnetic resonance imaging. Relationships between fALFF and clinical measurements, including number of depressive episodes and illness duration, were examined.

RESULTS

Compared to patients with remitted MDD and to healthy controls, patients with recurrent MDD exhibited decreased fALFF in the right posterior insula and right precuneus and increased fALFF in the left ventral anterior cingulate cortex. Decreased fALFF in the right precuneus and increased fALFF in the right middle insula were correlated with the number of depressive episodes in the recurrent MDD groups (r = -0.75, P < .01 and r = 0.78, P < .01, respectively) and remitted MDD groups (r = -0.63, P < .01 and r = 0.41, P = .03, respectively). In addition to regions in the default mode network (DMN) and salience network, the altered resting-state activity in the middle temporal and visual cortices was also identified.

CONCLUSIONS

Altered resting-state activity was observed across several neural networks in patients with recurrent MDD. Consistent with the emerging theory that altered DMN activity is a risk factor for depression relapses, the association between reduced fALFF in the right precuneus and number of depressive episodes supports the role of the DMN in the pathology of recurrent depression.