Poor Sleep as a Risk Factor for Nonsuicidal Self-Injury in Adolescent Girls

The purpose of this study was to examine the relation between poor sleep and nonsuicidal self-injury (NSSI), and to test the
hypothesis that poor sleep is a risk factor for the development of NSSI in young adolescents. Questionnaire data were used
from a 2-wave longitudinal study of a community sample of 881 young Swedish adolescents. The results showed that 7 % of the
girls reported poor sleep (never or seldom sleeping well), and 20–26 % of the girls reported repeated NSSI (at least 5 instances).
Poor sleep was associated prospectively with NSSI among girls, but not among boys. Of girls who responded that they seldom
or never slept well at T1, 77 % reported repeated NSSI 1 year later. Poor sleep at T1 was found to predict the incidence of
new cases of repeated NSSI in girls at T2, independently of their degree of psychopathology. No similar relationship between
poor sleep and NSSI was found in boys. The present results suggest that screening for poor sleep in adolescents may serve
to identify a subgroup of girls at risk for developing NSSI. It is concluded that poor sleep in young girls should be taken
seriously, even in the absence of other self-reported psychological problems, and that interventions targeted at sleep disturbances
may be important for prevention.