Association between sleep complaints and quality of life and the mediating role of substance use disorders: results from a nationally representative sample

Introduction

Sleep quality is associated with diminished quality of life. Substance use disorders (SUD) may constitute one leading contributory factor to this relationship.

Methods

In a nationally representative sample of US adults aged 18 years or older who were interviewed 3 years apart in the National Epidemiologic Survey on Alcohol and Related Conditions (wave 1, 2001–2002; wave 2, 2004–2005), we used structural equation modeling to examine the shared and specific effects of three sleep complaints at Wave 1 (i.e., trouble falling asleep, early morning awakening, and hypersomnia) on physical and mental health-related quality of life at Wave 2, based on SF-12v2 norm-based physical (PCS) and mental (MCS) scores. We estimated the proportions of these associations mediated by SUD, adjusting for various sociodemographic and clinical characteristics.

Results

Sleep complaints were significantly associated with lower MCS and PCS scores among the 34,653 respondents who completed both interviews (β = −0.094, SE = 0.010, p < 0.001; β = −0.042, SE = 0.009, p < 0.001, respectively). These associations were not specific to one type of sleep complaint, but rather were mediated by a single latent factor, representing mechanisms shared by all sleep complaints. A total of 14.42 % and 18.4 % of the effect of that latent factor on MCS and PCS was mediated by a SUD latent factor, representing the shared effects across SUDs.

Conclusion

Our findings highlight the importance of adopting dimensional approaches to model the co-occurrence of SUDs and sleep disturbance and suggest the importance of prevention and treatment measures for SUDs among adults with sleep disturbance.