Salivary beta-endorphin in nonsuicidal self-injury: an ambulatory assessment study

Lisa M Störkel,Johanna Hepp,Inga Niedtfeld,Iris-Tatjana Kolassa,Christian Schmahl,Alexander Karabatsiakis

doi:10.1038/s41386-020-00914-2

Abstract

Nonsuicidal self-injury (NSSI) is a prevalent and impairing behavior, affecting individuals with and without additional psychopathology. To shed further light on biological processes that precede and result from NSSI acts, we built on previous cross-sectional evidence suggesting that the endogenous opioid system, and especially β-endorphin, is involved in the psychopathology of NSSI. This is the first study assessing salivary β-endorphin in daily life in the context of NSSI acts. Fifty-one female adults with repetitive NSSI participated over a period of 15 days in an ambulatory assessment study. Salivary β-endorphin was assessed before and after engagement in NSSI, during high urge for NSSI, and on a non-NSSI day. Furthermore, NSSI specific variables such as pain ratings, as well as method, severity, and function of NSSI were assessed. We found that β-endorphin levels immediately before an NSSI act were significantly lower than directly after NSSI. However, there was no difference between β-endorphin during high urge for NSSI and post NSSI measures. We found a positive association between severity of the self-inflicted injury and β-endorphin levels, but no significant association between β-endorphin levels and subjectively experienced pain. The results of the present study indicate that it is possible to assess salivary β-endorphin in daily life in the context of NSSI. Furthermore, our results provide a first indication that NSSI acts could be associated with a momentary increase of β-endorphin, and this might reinforce NSSI engagement. More research is needed to replicate and extend our findings on peripheral β-endorphin in daily life.

Highlights

Nonsuicidal self-injury (NSSI) is defined as the intentional and deliberate damage of one’s own body tissue without suicidal intent [1]
Thereby, we focus on the question if NSSI could be used to initiate a release of β-endorphin by directly assessing the effect of real-life NSSI on the endogenous opioid system (EOS), using a within subjects design
We found that immediately before NSSI, βendorphin levels were significantly lower as compared to post NSSI samples. This finding supports theoretical assumptions of the homeostasis model of NSSI [26, 31], that individuals use NSSI to return to their intraindividual norm-physiological βendorphin range [18, 26, 30]

Summary

Introduction

Nonsuicidal self-injury (NSSI) is defined as the intentional and deliberate damage of one’s own body tissue without suicidal intent [1]. It is considered as a transdiagnostic symptom, but is prevalent in affective disorders and borderline personality disorder (BPD) [2, 3]. In studies using self-report measures, those with NSSI indicated a reduction in negative feelings and aversive tension as their primary motive [10]. Studies using ambulatory assessment (AA) demonstrated a reduction in negative affect and aversive tension following NSSI [2, 13]. Likewise, decreased amygdala activation through pain was observed in samples of BPD individuals with

Methods

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Discussion

Conclusion