Introduction:

Non-suicidal self-injury (NSSI) in adolescents has increased in recent years and constitutes a public health problem. A worldwide NSSI prevalence of 17.7% has been found, and it is higher in females. The objective of this review is to analyze and summarize the evidence on the association of lifestyle habits and problem behavior with NSSI in adolescents.

Methods:

We searched cohort and case–control studies in Medline, Embase and APA PsycInfo with no date or language restrictions. The study protocol was registered in PROSPERO (CRD42024501154). People aged 10 to 19 years with established exposure factors (sleeping habits, physical activity, eating habits, toxic habits or problematic use of technology devices) were compared to those with no exposure factors. The main outcome was the proportion of patients with NSSI. Meta-analyses were carried out following the Cochrane methodology.

Results:

Out of 5295 identified records, a total of 13 cohort studies were included (43% of moderate quality, 36% of poor quality and 21% of high quality). The results showed a statistically significant increase in the risk of NSSI with regular smoking (OR 2.89; IC 95% 1.42-5.90; I2 58%; two studies), alcohol (two studies), early cannabis use (aOR 1.42; IC 95% 1.13-1.75; one study), and poor physical activity (OR 0.49; 0.41-0.58; one study). No significant association was found between NSSI and substance use in one study. Inconsistent results were found for the use of technology devices and sleep quality.

Conclusions:

The results of this review show that regular smoking, alcohol use, early cannabis use and poor physical activity could increase the risk of NSSI in adolescents. The role of other factors like sleeping habits or use of technology devices is still uncertain. More longitudinal studies with longer follow-up are needed to extract firm conclusions.