Functional MRI of pain application in youth who engaged in repetitive non-suicidal self-injury vs. psychiatric controls.

Non-suicidal self-injury (NSSI) is increasingly common in young psychiatric patients. It is unclear why pain, which should be aversive, becomes reinforcing in this context. We hypothesized that pain- and/or reward-processing neurocircuitry would be abnormal in NSSI patients compared with non-NSSI patients. Using functional magnetic resonance imaging, we administered a painfully cold and comparison cool stimulus under two conditions: self-administered and experimenter-administered (as a control). Participants comprised 13 NSSI patients and 15 non-NSSI control patients, who were matched for sex, age, medications, symptoms, and diagnoses. Whole-brain analyses of main effects, as well as correlational analyses with subjective pain and "relief" (suggesting reward), were performed. Significant main effects of group showed greater blood oxygenation level-dependent (BOLD) response for NSSI than controls in right midbrain/pons; culmen; amygdala; and parahippocampal, inferior frontal and superior temporal gyri; as well as orbital frontal cortex (OFC). The correlation between BOLD signal and "relief" was greater in NSSI patients in areas associated with reward/pain and addiction including thalamus, dorsal striatum and anterior precuneus. Post hoc analysis showed reduced functional connectivity between right OFC and anterior cingulate cortex in NSSI youth, implying possible deficits in the neuroregulation of emotional behavior. These findings help inform how pain is associated with reward for NSSI patients but not for non-NSSI patients.