RESUMO
BACKGROUND: Non-suicidal self-injury (NSSI) is a serious and common phenomenon which has been linked with emotion or affect regulation. The capacity for top-down emotion regulation has also been linked to vagal tone. Vagal tone is known to be low in groups with a propensity to engage in NSSI. HYPOTHESIS: Some forms of NSSI, both direct and indirect, may result in vagal stimulation. The resulting increase in vagal tone may be linked to activation of prefrontal areas and improved top-down emotion regulation. This may be a maintaining factor in NSSI. EVALUATION: Cutting with the sight of blood, the use of ligatures, eating disorders and risky sexual behaviour, behaviours that could be considered direct or indirect forms of NSSI, are all plausible methods of vagal self-stimulation. CONCLUSION: NSSI may increase vagal tone. This may result in improved top down emotion regulation and result in a calmer emotional state. These vagal effects may be important maintaining factors in self-harm. This has important implications for the study and possible management of a common and serious issue.
