|dc.description.abstract||Major depression is a debilitating and highly recurrent mental illness that typically emerges during adolescence (Hankin, 2006). The increased vulnerability to depression observed during adolescence is posited to arise in part from major neurobiological changes that occur during typical development (Davey, Yücel, & Allen, 2008). Importantly, these neurobiological changes occur while the adolescent’s focus shifts from parents to peers (Steinberg, 2005). Social reward (e.g., peer acceptance) is therefore thought to be particularly salient, and a failure to obtain social reward (e.g., through social rejection) has been implicated as a driving force in the vulnerability to and maintenance of adolescent depression (Davey et al., 2008; Mellick, Sharp, & Ernst, 2015). Indeed, social rejection during adolescence is highly predictive of depression (Prinstein & Aikens, 2004), and currently depressed adolescents experience more rejection than their healthy peers (Lee, Hankin, & Mermelstein, 2010). Several adult and youth depression studies have examined response to social rejection revealing greater distress among depressed individuals; however, these studies relied predominantly on self-report or behavioral data. Therefore, the neurobiological underpinnings of rejection in depression remain underexplored despite the fact that such findings may inform etiological and theoretical models of depression, helping to further classify depression in terms of neural circuitry.
Against this background, a total of N = 35 adolescents were recruited to form two groups (Depressed, n = 17; Healthy controls, n = 18) who experienced rejection during fMRI scanning. This study had two aims: 1) To compare neural response to peer rejection in depressed adolescents versus healthy controls, and 2) To examine sex as a moderator of the relation between depression and neural response to rejection. Whole-brain voxel-wise and region of interest (ROI) between-group analyses were performed. Whole-brain results showed depressed adolescents to exhibit significantly greater rejection response in the right anterior insula, left occipital operculum, and left nucleus accumbens. Reduced ventral striatal response to social inclusion was not found in depressed adolescents. ROI analyses led to null findings with no significant differences observed between groups. Insufficient samples sizes prohibited examining sex as a moderator. Exploratory tests of pubertal x group effects were conducted though non-significant, which was presumably due to limited data. Positive and null results are discussed in relation to extant neuroimaging findings in healthy and depressed samples with an emphasis on discrepancies across studies which may be due to methodological differences. The present study was among the few to recently employ Cyberball in the study of psychiatric populations marked by interpersonal functioning deficits and contributes to the identification of unique and/or shared neural substrates of an important interpersonal process in adolescent depression.||