Atypical intra- and inter-regional coupling patterns involved in repetitive non-suicidal self-injury.

OBJECTIVE

Non-suicidal self-injury (NSSI) is becoming more common among youth with major depressive disorder (MDD). Repetitive NSSI (R-NSSI), a severe type of NSSI, is a growing concern. As a behavioural addiction, R-NSSI may be closely linked to aberrant response inhibition. This study aimed to investigate the neural correlation of response inhibition within R-NSSI.

METHODS

A total of 85 youths participated in a Go/NoGo task during magnetoencephalography scanning, including 27 MDD youths with R-NSSI, 28 MDD youths without NSSI and 30 healthy controls. Phase amplitude coupling and functional connectivity were calculated to detect the intra- and inter-regional coupling patterns. Further, phase slope indexes were used to ascertain the brain information flow direction.

RESULTS

Locally, the R-NSSI group showed hyper-coupling of gamma amplitude and beta phase within the temporal region. Globally, connectivity within the prefrontal cognitive control circuit, mediated by both beta and gamma oscillations, was diminished. Notably, the R-NSSI group showed a negative frontoparietal information flow contrasted with a positive temporoparietal information flow. Furthermore, the strength of functional connectivity mediated the association between NSSI and childhood trauma.

CONCLUSIONS

Our findings suggest disrupted local and regional control processes in youths with R-NSSI. Overall, NSSI manifests an inefficient prefrontal network compensated by enhanced activity in temporal lobe regions. These results offer electrophysiological insights into the neural mechanisms of NSSI.