Wednesday, March 21, 2018

Study Offers Clues About Neural Biomarkers of Resilience to Depression


While numerous studies have examined risk factors for the transmission of familial depression, fewer have explored the factors that might protect individuals from developing this disorder. A report published today in JAMA Psychiatry suggests adolescent girls who appear resilient to depression may have greater connectivity in brain networks known to play a key role in the processing and regulation of emotion, motivation, and self-awareness.

For this longitudinal study, Adina S. Fischer, M.D., Ph.D., of Stanford University and colleagues conducted clinical and behavioral assessments every 18 months on a group of girls from age 9 to 18. Half of the girls had a mother who had recurrent major depressive disorder (MDD) episodes during her daughter’s lifetime (high risk); the other half had mothers with no history of depression (low risk). Approximately six years after the start of the study, adolescents in the high-risk and low-risk groups received a resting-state functional magnetic resonance imaging (fMRI) scan.

Fischer and colleagues compared data from the fMRI scans of 20 adolescents in the high-risk group who did not develop MDD (resilient) with 20 in the high-risk group who developed MDD (converted) and 25 adolescents in the low-risk group who did not develop depression (control).

Compared with adolescents who developed depression and those in the control group, adolescents in the resilient group had greater connectivity between the amygdala and prefrontal cortex—two regions known to be involved with emotion processing and regulation. Resilient adolescents also had greater connectivity between regions of the executive control network (implicated in explicit emotion regulation, including cognitive reappraisal and impulse control) than did adolescents who developed depression and the control peers. Both high-risk groups (resilient and converted) differed from controls in salience network connectivity, with the strongest salience network connectivity in the converted group. (The salience network is implicated in self-awareness and integrating stimuli.)

“Our findings suggest that high-risk adolescent females in the resilient group have greater ‘top-down’ control over emotions and behavior than do high-risk adolescent females who develop depression. … [T]his provides a possible mechanism and target through which therapeutic interventions aimed at strengthening these connections could increase resilience in high-risk populations.”

In an accompanying editorial, Scott A. Langenecker, Ph.D., and colleagues at the University of Illinois at Chicago wrote, “The work of Fischer and colleagues provides an important foundation for studying neurobiological factors, such as functional connectivity, that may reflect resilience for daughters of depressed mothers. … This type of work ultimately increases our understanding of promotive factors that can be strengthened, existing techniques that facilitate resilience, and the ways in which these techniques might be improved and more widely disseminated.”

For related information on resilience to psychiatric disorders, see the American Journal of Psychiatry article “The Role of Intrinsic Brain Functional Connectivity in Vulnerability and Resilience to Bipolar Disorder.”

(Image: iStock/Henrik5000)