To explore the longitudinal relationships between sleep problems and non-suicidal self-injury (NSSI) behaviors in college students, so as to provide a theoretical basis for the prevention and intervention of NSSI.

In October 2023 (T1), a total of 1 009 college students from two provincial colleges in Guangdong were selected by using a combination of convenience sampling and stratified cluster random sampling for a 1-year follow-up survey (October 2024, T2). The students were assessed by using the Insomnia Severity Index(ISI), Non-restorative Sleep Scale(NRSS), Epworth Sleepiness Scale (ESS), and Adolescent Non-suicidal Self-injury Assessment Questionnaire(ANSAQ). Data analysis was performed using McNemar's test and Logistic regression.

The detection rate of NSSI behaviors was 18.83% at T1 and decreased to 7.73% at T2, with a statistically significant difference (χ²=66.24, P < 0.01). The trajectories of NSSI behaviors were divided into persistent group (4.06%), new-onset group (3.67%), remission group (14.77%), and resistance group (77.50%). Logistic regression analysis showed that sleep less than 7 hours per day at night, insomnia (mild, moderate-to-severe), non-restorative sleep (moderate, severe), daytime sleepiness, and weekly nightmare frequency (1-2, ≥3 times) were associated with NSSI behaviors at T1 (OR=5.02, 2.39, 5.51, 3.47, 9.70, 2.36, 2.63, 4.74, all P < 0.01). Insomnia (mild, moderate-to-severe), severe non-restorative sleep, daytime sleepiness, and weekly nightmares ≥3 times at T1 all increased the risk of NSSI behaviors at T2 (OR=1.76, 4.15, 4.05, 1.88, 5.63, all P < 0.05). Moderate-to-severe insomnia, severe non-restorative sleep, daytime sleepiness, and weekly nightmares ≥3 times at T1 increased the risk of belong to the new-onset NSSI group (OR=5.05, 3.37, 2.08, 5.86, all P < 0.05).

Insomnia, non-restorative sleep, daytime sleepiness, and frequent nightmares are important risk factors for NSSI behaviors among college students. Early assessment and intervention of sleep problems may be an important strategy for the prevention and treatment of NSSI.