Abstract

OBJECTIVES:

Young people are sleeping less. Short sleep duration has a range of negative consequences including a hypothesized link with psychological distress, which has yet to be studied

DESIGN:

Prospective cohort study

SETTING:

Community-based sample from Australia

PARTICIPANTS:

Twenty thousand (20,822) young adults (aged 17-24) identified through the state vehicle licensing authority. A random sample (n = 5000) was approached for follow-up 12-18 months later, with 2837 providing full data.

MAIN OUTCOME MEASURE:

Psychological distress, determined by a Kessler 10 score > 21, at baseline; and as both onset and persistence of distress at follow-up.

RESULTS:

Shorter sleep duration was linearly associated with prevalent psychological distress: relative risk (RR) 1.14 (95% CI 1.12 to 1.15). Only the very short (< 5 h) sleepers among those not distressed at baseline had an increased risk for onset of psychological distress (RR 3.25 [95% CI 1.84, 5.75]). Of 945 cohort participants reporting psychological distress at baseline, 419 (44%) were distressed at follow-up. Each hour less of sleep increased the risk of psychological distress persisting after adjustment for potential confounding variables: RR 1.05 (95% CI 1.01 to 1.10). Long sleep duration showed no association with distress at any time point.

CONCLUSIONS:

Self-reported shorter sleep duration is linearly associated with prevalent and persistent psychological distress in young adults. In contrast, only the very short sleepers had a raised risk of new onset of distress. Different approaches to sleep duration measurement yield different results and should guide any interventions to improve subjective sleep duration in young adults.