Lifestyle habits, problem behaviors and non-suicidal self-injury in adolescents: a systematic review with meta-analysis of longitudinal studies

Some lifestyle habits and problematic behaviors have been associated to non-suicidal self-injury (NSSI) in adolescents in cross-sectional studies but their role as individual risk factors needs to be analyzed through proper longitudinal designs. The objective is to analyze and summarize the evidence on the association of lifestyle habits and problem behaviors with NSSI in adolescents. Longitudinal studies were searched in Medline, Embase and APA PsycInfo without date or language restrictions. Adolescents with and without exposure factors were compared. Out of 5295 identified records, 13 longitudinal studies were included (39,575 participants). Studies included different age ranges (10-20 years, mean 14.3, SD 2.4), and 78% were female. Results showed a statistically significant increased risk of NSSI with regular smoking, alcohol use, early cannabis use, and poor physical activity. Inconsistent results were found for use of technology and sleep habits, and no studies analyzed dietary habits or gambling. Most studies were of moderate or high quality but certainty of the evidence was very low according to GRADE criteria. Longitudinal evidence suggests that some lifestyle habits and problem behaviors are risk factors for NSSI in adolescents. These findings highlight the importance of developing strategies to promote healthy lifestyles in adolescents.