# Sleep problems, decision-making, and suicide attempts during adolescence: a longitudinal birth cohort study

## TL;DR

This study finds that sleep problems in adolescents are linked to a higher risk of suicide attempts later, and that decision-making skills can influence this relationship.

## Contribution

This is the first longitudinal study examining how sleep problems, decision-making, and risk-taking interrelate with adolescent suicide attempts.

## Key findings

- Shorter sleep time on school days and frequent night awakenings were linked to higher suicide attempt risk.
- Rational decision-making reduced the risk associated with frequent night awakenings.
- The study highlights sleep deprivation and fragmentation as potential targets for suicide prevention.

## Abstract

Sleep problems have been identified as a risk factor for suicidal thoughts and behaviors 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 moderate this relationship.

This analysis utilized data from waves 6 (14 years) and 7 (17 years) in the Millennium Cohort Study (MCS; n = 8524, female = 4369 [51.26 per cent]), a UK population-representative longitudinal study of youth born between 2000 and 2002. 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.

Shorter total time in bed on school days (OR = 0.88; 95% CI = 0.80 to 0.96; p = .004) and more frequent night awakenings (OR = 1.15; 95% CI = 1.07 to 1.23; p ≤ .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 to 3.37; p = .002) moderated the association between night awakenings and attempted suicide.

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 etiology of adolescent suicide behavior and highlight sleep deprivation and fragmentation as potential preventative targets for suicide attempts.

Statement of SignificanceThe development of adolescents coincides with the emergence of sleep problems and suicide-related behavior. Nevertheless, the influence of poor sleep on prospective adolescent suicide risk and relevant contributing factors remains unclear. This is the first longitudinal study examining the interrelationships between sleep, risk-taking and decision-making, and adolescent suicide attempts. Suicide attempt history at 17 years was associated with more frequent night awakenings and shorter total time in bed on school days at 14 years, and rational decision-making moderated this former association. These findings can inform suicide preventative interventions, highlighting the relevance of assessing and treating sleep deprivation and fragmentation. Future prospective studies utilizing multiple data waves should further examine the moderating mechanisms on the relationship between poor sleep and suicide risk.

The development of adolescents coincides with the emergence of sleep problems and suicide-related behavior. Nevertheless, the influence of poor sleep on prospective adolescent suicide risk and relevant contributing factors remains unclear. This is the first longitudinal study examining the interrelationships between sleep, risk-taking and decision-making, and adolescent suicide attempts. Suicide attempt history at 17 years was associated with more frequent night awakenings and shorter total time in bed on school days at 14 years, and rational decision-making moderated this former association. These findings can inform suicide preventative interventions, highlighting the relevance of assessing and treating sleep deprivation and fragmentation. Future prospective studies utilizing multiple data waves should further examine the moderating mechanisms on the relationship between poor sleep and suicide risk.

Graphical Abstract