Does mental health history explain gender disparities in insomnia symptoms among young adults?

Background: Insomnia is the most commonly reported sleep disorder, characterized by trouble falling asleep, staying asleep, or waking up too early. Previous epidemiological data reveal that women are more likely than men to suffer from insomnia symptoms. We investigate the role that mental health history plays in explaining the gender disparity in insomnia symptoms. Methods: Using logistic regression, we analyze National Health and Nutritional Examination Survey (NHANES) III interview and laboratory data, merged with data on sociodemographic characteristics of the residential census tract of respondents. Our sample includes 5469 young adults (ages 20-39) from 1429 census tracts. Results: Consistent with previous research, we find that women are more likely to report insomnia symptoms compared to men (16.7% vs. 9.2%). However, in contrast to previous work, we show that the difference between women's and men's odds of insomnia becomes statistically insignificant after adjusting for history of mental health conditions (OR = 1.08, p > .05). Conclusions: The gender disparity in insomnia symptoms may be driven by higher prevalence of affective disorders among women. This finding has implications for clinical treatment of both insomnia and depression, especially among women. (C) 2009 Elsevier B.V. All rights reserved.