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Brain activation patterns during reward processing tasks are associated with depression severity and treatment outcomes in late-life depression (LLD), according to study results published in The American Journal of Geriatric Psychiatry.
Network dysfunctions in the brain, including in those related to processing emotional information and the reward system, have been linked to LLD and poor treatment responses among patients. In the current study, researchers sought to examine whether brain activation in reward, salience, and default mode network (DMN) regions during a Probabilistic Reversal Learning (PRL) task are linked to response to psychotherapies for LLD.
Participants were assigned to 9 weekly sessions of Engage psychotherapy or Problem-Solving Therapy (PST). They underwent fMRI scans at baseline and week 6 of treatment. Researchers measured depression symptom severity using the Hamilton Depression Rating Scale (HAM-D) at baseline and weeks 2, 4,6, and 9. To examine reward response and brain activity, participants performed the Probabilistic Reversal Learning Task in the MRI scanner. Finally, psychotherapy treatments included the Engage and Problem-Solving Therapy treatments.
The final sample included 33 participants aged 60 years and older. Lower baseline activation in the left dACC (F1,81=5.25, P=.024) and right sgACC (F1,78=6.60, P=.012) was associated with reduced depression severity over six weeks of psychotherapy. At week 6, lower right dACC activation (F1,72=11.20, P=.001), higher right sgACC activation (F1,83=5.88, P=.02), and higher right NAcc activation (F1,79=9.37, P =.003) were also linked to lower depression severity.
Behaviorally, baseline faster response times following positive feedback (F1,44=6.81, P=.01) and slower response times following negative feedback (F1,47=8.78, P=.0004) correlated with lower depression severity over the treatment period.
Exploratory whole-brain analysis identified consistent activation in reward, salience, and cognitive control networks during a PRL task. At baseline, the orbitofrontal gyrus, posterior cingulate, and right caudate were more active during positive feedback, while regions of the dorsolateral prefrontal cortex (DLPFC), posterior parietal cortex, left middle frontal gyrus, left thalamus, and bilateral anterior insula showed greater activation during negative feedback. This pattern persisted at week 6, with no significant changes in activation contrasts between baseline and week 6.
The study authors concluded, “Older depressed adults who present with lower activation of the salience network and DMN may experience the most benefit from psychotherapy.”
Study limitations include a small sample size, lacking diversity, and not examining whole functional networks.
One study author reported affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
This article originally appeared on Psychiatry Advisor
