Differential engagement of cognitive control regions and subgenual cingulate based upon presence or absence of comorbid anxiety with depression.

BACKGROUND: Major depressive disorder (MDD) and anxiety disorders are highly comorbid, sharing many similar symptoms, including impairments in cognitive control. Deficits in cognitive control could be a potential mechanism underlying impaired emotion regulation in mood disorders. METHODS: Participants were 44 individuals with no history of mental illness (healthy controls, HC), 31 individuals in the remitted state of MDD (rMDD), and 18 individuals who met lifetime DSM-IV-TR criteria for rMDD and an anxiety disorder in remission (Comorbid). Participants completed a Parametric Go/No-Go (PGNG) test during fMRI. Event-related analyses modeled activity for cognitive control successes (Hits for Targets, Rejections for Lures) and failures (Commissions on Lures) on the PGNG task. RESULTS: The rMDD group showed significantly reduced activity within the cognitive control network (CCN) during Commission errors, including the middle frontal gyrus and inferior parietal lobule (IPL). The Comorbid group showed significantly reduced activity in several clusters within the CCN during correct Rejections, including the left IPL and right inferior frontal gyrus and greater subgenual cingulate. Notably, during correct Rejections, 60% of activation for the Comorbid group was within the Salience and Emotion Network (SEN), with 0% within the CCN. LIMITATIONS: The size of the Comorbid subgroup was modest, preventing subanalysis of the different AD subtypes. CONCLUSIONS: There is evidence that CCN activity declines in rMDD and that there may be compensatory SEN activity in individuals with Comorbid rMDD and anxiety. Our findings support the identification of comorbid anxiety as a meaningful subtype of MDD that may obscure group differences between rMDD and HCs.

Individuals with more severe depression fail to sustain nucleus accumbens activity to preferred music over time.

We investigated the ability of preferred classical music to activate the nucleus accumbens in patients with Major depressive disorder (MDD). Twelve males with MDD and 10 never mentally ill male healthy controls (HC) completed measures of anhedonia and depression severity, and listened to 90-second segments of preferred classical music during fMRI. Compared to HCs, individuals with MDD showed less activation of the left nucleus accumbens (NAcc). Individuals with MDD showed attenuation of the left NAcc response in later compared to earlier parts of the experiment, supporting theories that MDD involves an inability to sustain reward network activation. Counter intuitively, we found that NAcc activity during early music listening was associated with greater depression severity. In whole-brain analyses, anhedonia scores predicted activity in regions within the default mode network, supporting previous findings. Our results support theories that MDD involves an inability to sustain reward network activation. It also highlights that pleasant classical music can engage critical neural reward circuitry in MDD.