Sleep Problems, Decision-Making, and Suicide Attempts During Adolescence: A Longitudinal Birth Cohort Study

Study Objectives
Sleep problems have been identified as a risk factor for suicidal thoughts and behaviours during adolescence, yet a lack of longitudinal mechanistic investigation into contributing factors (e.g., cognitive functioning) limits understanding of the temporality and specificity of this relationship. This study investigates the impact of sleep problems on subsequent reported suicide attempt, and whether risk-taking and decision-making moderates this relationship.

Methods
This analysis utilised data from waves 6 (14 years) and 7 (17 years) in the Millennium Cohort Study (MCS; n=8,524, Female=4,369 [51.26%]), a UK population-representative longitudinal study of youth born between 2000-02. Self-reported sleep items assessed at 14 years were used to calculate total time in bed on school and non-school nights, social jetlag, sleep onset latency, and frequency of night awakenings. Self-reported attempting suicide was measured at 17 years. The Cambridge Gambling Task assessed risk-taking and decision-making at 14 years.

Results
Shorter total time in bed on school days (OR=0.88; 95% CI=0.80-0.96; P=0.004) and more frequent night awakenings (OR=1.15; 95% CI=1.07-1.23; P=<0.001) were prospectively associated with subsequent reported suicide attempt, even when controlling for demographic and clinical covariates. Rational decision-making (OR=2.12; 95% CI=1.33-3.37; P=0.002) moderated the association between night awakenings and attempted suicide.

Conclusions
Shorter total time in bed and more frequent night awakenings heightened suicide risk in adolescents, and this latter relationship was modified by rational decision-making. These results provide insight into the aetiology of adolescent suicide behaviour and highlight sleep deprivation and fragmentation as potential preventative targets for suicide attempts.