Enhanced default mode network connectivity with ventral striatum in subthreshold depression individuals

Abstract

Subthreshold depression (StD) is a highly prevalent condition associated with increased service utilization and social morbidity. Nevertheless, due to limitations in current diagnostic systems that set the boundary for major depressive disorder (MDD), very few brain imaging studies on the neurobiology of StD have been carried out, and its underlying neurobiological mechanism remains unclear. In recent years, accumulating evidence suggests that the disruption of the default mode network (DMN), a network involved in self-referential processing, affective cognition, and emotion regulation, is involved in major depressive disorder. Using independent component analysis, we investigated resting-state default mode network (DMN) functional connectivity (FC) changes in two cohorts of StD patients with different age ranges (young and middle-aged, n= 57) as well as matched controls (n=79). We found significant FC increase between the DMN and ventral striatum (key region in the reward network), in both cohorts of StD patients in comparison with controls. In addition, we also found the FC between the DMN and ventral striatum was positively and significantly associated with scores on the Center for Epidemiologic Studies Depression Scale (CES-D), a measurement of depressive symptomatology. We speculate that this enhanced FC between the DMN and the ventral striatum may reflect a self-compensation to the lowered reward function.

Acupuncture treatment modulates the corticostriatal reward circuitry in major depressive disorder

“…A core characteristic of patients with depression is the loss of interest in pleasurable activities and limitations in multiple dimensions of well-being (Bogdan, Nikolova, & Pizzagalli, 2013; Hasler & Northoff, 2011; Hwang et al, 2016; Naranjo, Tremblay, & Busto, 2001; Russo & Nestler, 2013). The reward system (Bluhm et al, 2009; Naranjo et al, 2001; Pizzagalli et al, 2009) is involved in pleasure and motivation, which have been proven to play important roles in the pathophysiology of MDD (Bluhm et al, 2009; Soares et al, 2008).…”

Anatomical brain difference of subthreshold depression in young and middle-aged individuals

“…We found that the resting state functional connectivity between the subgenual ACC and the default mode network was significantly associated with symptom severity in StD patients (Hwang et al, 2016). The abnormal function and structure of the ACC/mPFC has been regarded as a biomarker in MDD (Phillips et al, 2015).…”

Repeated acupuncture treatments modulate amygdala resting state functional connectivity of depressive patients

“…Pizzagalli, 2011, Silbersweig, 2013). Many brain regions including the amygdala, hippocampus, insula, ventral striatum, ventral anterior cingulate gyrus, and prefrontal cortex are involved in the neural pathology and development of MDD (Lawrence et al, 2004, Phillips et al, 2015, Phillips et al, 2003a, Phillips et al, 2003b) and subthreshold depression (Hwang et al, 2016). Among these brain regions, one of the most well-studied regions is the amygdala.…”