Social anhedonia and medial prefrontal response to mutual liking in late adolescents

Abstract

Anhedonia, a cardinal symptom of depression defined as difficulty experiencing pleasure, is also a possible endophenotype and prognostic factor for the development of depression. The onset of depression typically occurs during adolescence, a period in which social status and affiliation are especially salient. The medial prefrontal cortex (mPFC), a region implicated in reward, self-relevant processing, and social cognition, exhibits altered function in adults with anhedonia, but its association with adolescent anhedonia has yet to be investigated. We examined neural response to social reward in 27 late adolescents, 18-21years old, who varied in social anhedonia. Participants reported their social anhedonia, completed ratings of photos of unfamiliar peers, and underwent a functional magnetic resonance imaging task involving feedback about being liked. Adolescents with higher social anhedonia exhibited greater mPFC activation in response to mutual liking (i.e., being liked by someone they also liked) relative to received liking (i.e., being liked by someone whom they did not like). This association held after controlling for severity of current depressive symptoms, although depressive severity was also associated with greater mPFC response. Adolescents with higher levels of social anhedonia also had stronger positive connectivity between the nucleus accumbens and the mPFC during mutual versus received liking. These results, the first on the pathophysiology of adolescent anhedonia, support altered neural reward-circuit response to social reward in young people with social anhedonia.

Keywords: Adolescence; Anhedonia; Depression; Medial prefrontal cortex; Reward; Social cognition.

Figure 1

Block-design social reward fMRI task included in the current study. The task was adapted from the work of Davey et al. (2010). Participants rated 20 female and 20 male face stimuli on how much they imagined that they would like each person. Ratings were used to create personalized stimulus sets for the 3 block types: mutual liking (positive feedback, from most-liked faces), received liking (positive feedback, from least-liked faces), and ambiguous (no feedback, from neutral faces).

Figure 2

Late adolescents’ social anhedonia (RSAS; Eckblad et al., 1983) in relation to medial prefrontal cortex (mPFC) response (in arbitrary units, extracted from cluster mean) to mutual liking relative to received liking. The large cluster yielded by this analysis includes the following subregions of the mPFC: dorsal mPFC, pregenual anterior cingulate cortex, and rostral mPFC. Scatterplots depict the association between social anhedonia score and mPFC response (extracted as the mean across the entire cluster), for illustration purposes.

Figure 3

Late adolescents’ social anhedonia (RSAS; Eckblad et al., 1983) in relation to positive functional connectivity between the bilateral nucleus accumbens and the mPFC during mutual liking relative to received liking. Two large clusters yielded by this analysis include the following subregions of the mPFC: (1) dorsal mPFC and (2) pregenual anterior cingulate, rostral mPFC, and anterodorsal mPFC. Scatterplots depict psychophysiologic interaction (PPI) values, (extracted as the mean across the entire larger cluster), for illustration purposes. R² value reflects the effect size of the association between social anhedonia and the mean PPI value across the depicted cluster.