A bidirectional link between non-suicidal self-injury (NSSI) and insomnia was found on the basis of longitudinal questionnaire data. These results were published in the Journal of Sleep Research.
The first 3 years of a 5-year longitudinal study were analyzed. Adolescents (N=1457) attending 18 public schools in Sweden were surveyed for symptoms of insomnia, self-harm, depression, worry, rumination, impulsive, and NSSI behaviors.
At baseline, participants ranged in age from 12 to 15 years, 52.7% were boys, and 69.9% lived in a 2-parent household. The retention rates were 91.9% at year 2 and 81.3% at year 3.
After controlling for gender, the investigators observed a good fit between NSSI and insomnia (c2= 31.92; P <.001). NSSI behavior during the first survey predicted increased symptoms of insomnia at the second survey (b12 = 0.09; 95% CI, 0.03-0.15; P =.002) and NSSI behavior during the second predicted insomnia at the third (b23 = 0.12; 95% CI, 0.06-0.18; P <.001).
Although insomnia at year 1 did not predict NSSI at year 2 (b12 = 0.02; 95% CI, -0.06 to 0.09; P =.68) insomnia at year 2 was indicative of NSSI at year 3 (b23 = 0.09; 95% CI, 0.02-0.16; P =.01).
The investigators observed a pathway mediated by depression between NSSI and insomnia (b = 0.01; 95% CI, 0.002-0.02; P =.02; c2, 68.78; P =.00). No links between impulsivity (b = 0.01; 95% CI, 0.00-0.01; P =.07; c2, 72.65; P =.00), worry (b = 0.002; 95% CI, -0.01 to 0.01; P =.54; c2, 72.02; P =.00), or rumination (b = 0.00; 95% CI, -0.01 to 0.004; P =.59; c2, 99.72; P =.00) were significantly associated with NSSI and insomnia.
A limitation of this study was the focus on 4 main mediators between NSSI behavior and insomnia. It may be possible that other behaviors, including regulation of emotions, beliefs, and attitudes may be involved with the association between NSSI and insomnia.
The study authors concluded that a bidirectional link between self-harm behaviors and sleep difficulties existed among adolescents and that they likely maintain each other over time. These observations have clinical importance and may allow for clinicians to stratify patients who are at an increased risk for self-harm on the basis of sleep patterns. Although symptoms of depression in part explain the observed self-harm behaviors among adolescents, further studies are needed to better understand the relationship between self-harm, depression, and sleep difficulties and to explore possible avenues for effective interventions.
Latina D, Bauducco S, and Tilton-Weaver L. Insomnia symptoms and non-suicidal self-injury in adolescence: understanding temporal relations and mechanisms. J Sleep Res. 2020;00:e13190. doi.org/10.1111/jsr.13190