Suicidal Behaviour, Self-Harm and Related Factors: A Retrospective Study from the Adolescent Psychiatric Unit

<b><i>Background and objectives</i></b>: Suicide attempts and self-harm are critical issues in adolescence, often leading to serious and irreversible consequences. These behaviours frequently co-occur and share common biopsychosocial risk factors. Identifying these factors enables a more comprehensive assessment of suicide and self-harm risk, helping specialists recognize high-risk individuals and implement effective preventive measures. This study aimed to examine the association between suicide attempts, self-harm and psychosocial factors among hospitalized adolescents. <b><i>Materials and methods</i></b>: A retrospective data analysis was performed using the database of the University Department of Children and Adolescents of the Republican Vilnius Psychiatric Hospital. The study covered patients' records from December 2022 to February 2025. Information on gender, age, suicide attempts, self-harm, adverse events (bullying, psychological abuse, physical violence within the family, and sexual abuse) and unhealthy habits (smoking, harmful alcohol consumption, and psychoactive substance use), was selected and analyzed in this study. A Chi-square test was used to assess the difference between groups. Results were considered statistically significant when <i>p</i> < 0.05. <b><i>Results</i></b>: The study included 599 hospitalized adolescents (26.9% boys; mean age 15.1 ± 1.4 years), of whom 70.8% reported at least one episode of self-harm and 37.8% at least one suicide attempt. Rates of self-harm and suicide attempts were significantly higher in girls than in boys (self-harm: 81.3% vs. 42.2%, ϕ=0.381, p<0.001; suicide attempts: 45.5% vs. 16.5%, ϕ=0.304, p<0.001), and adolescents with self-harm had a significantly higher prevalence of suicide attempts than those without self-harm (46.7% vs. 15.8%, ϕ=0.308, p<0.001). Adverse childhood experiences and unhealthy behaviours were significantly more frequent in adolescents with self-harm and suicide attempts, although effect sizes were small to moderate (ϕ range 0.086-0.230, all p<0.05). In multivariable models, female gender (β=0.355, p<0.001) and smoking (β=0.330, p<0.001) were the strongest predictors of self-harm, whereas alcohol use (β=0.337, p<0.001) and self-harm (β=0.232, p<0.001). <b><i>Conclusions</i></b>: Exposure to adverse childhood experiences and engagement in unhealthy habits were associated with higher rates of both self-harm and suicide attempts. A comprehensive assessment and early detection of self-harm behaviours and adverse psychosocial circumstances are crucial elements of effective suicide prevention strategies and prompt intervention among high-risk adolescents.