Self-esteem and non-suicidal self-injury in adulthood: A systematic review.

Background: Non-suicidal self-injury (NSSI) is a self-destructive act that represents a considerable burden on the individual and society. Low self-esteem may be a psychological variable that is related to NSSI. However, little is
known about the nature of this relationship in adulthood. This systematic review therefore aimed to provide a synthesis of the available literature on the relationship between self-esteem and NSSI.

Methods: Articles were independently identified and risk of bias assessed by two reviewers searching PsycINFO, CINAHL, Medline and Web of Science databases. Inclusion criteria were: (1) a mean sample age of eighteen years or over (2) full manuscripts available in English (3) assessment of NSSI (4) assessment(s) of self-esteem. A narrative synthesis of results was undertaken. A random-effects meta-analysis of differences in self-esteem between
NSSI and non-NSSI groups was also undertaken.

Results: Seventeen studies were identified and indicated a significant negative relationship between self-esteem and NSSI. The meta-analysis indicated lower self-esteem in those with experiences of NSSI versus those without,
d = 0.59 – 1.17. Results suggested that although low self-esteem and NSSI are related in both clinical and nonclinical populations, there are a number of factors which also influence this relationship.

Limitations: The absence of longitudinal research is a major limitation of this literature.
Conclusions: It will be important for clinicians to consider the impact of self-esteem in those seeking support for NSSI. Further research should undertake longitudinal research to better understand the self-esteem and NSSI
relationship.