Altered functional connectivity of reward circuits in adolescents with addictive nonsuicidal self-injury

Non-suicide self-injury (NSSI) behavioral addiction may be related to impaired midbrain dopamine reward system. However, the underlying neural mechanisms remain unclear. The purpose of this study is to explore the alterations in resting-state functional connectivity (rs-FC) between regions of the reward circuits and the whole brain, and to elucidate the link between these rs-FC alterations and clinical characteristics among NSSI adolescents with addictive features.

A total of 37 unmedicated adolescents with NSSI were recruited, including 24 adolescents with addictive NSSI (aNSSI group), 13 adolescents with non-addictive NSSI (nNSSI group), and 25 healthy controls (HCs). Seed-based FC approach was used to examine the FC alterations between regions of the reward circuit and the whole brain. Subsequently, we employed Pearson's correlation analyses to evaluate the relationship between FC alterations and self-injury.

Relative to the nNSSI group, the aNSSI group showed increased in FC between left hippocampus and right caudate nucleus, as well as a decline in FC between left nucleus accumbens and bilateral medial cingulate gyrus, and between left amygdala and right inferior orbitofrontal gyrus. The FC between left hippocampus and right caudate nucleus was positively correlated with the self-injury frequency in the past month.

Our findings suggest that marked FC alterations between the amygdala, nucleus accumbens, and hippocampus and whole brain region among adolescents with addictive NSSI versus adolescents with non-addictive NSSI. Moreover, this alteration may be connected to the frequency of self-injury. These findings may provide new neuroimaging evidence for behavioral addiction of NSSI and for distinguishing the subtypes of NSSI.