OBJECTIVE: Nonalcoholic steatohepatitis (NASH) is a morbid liver disease with limited treatment. Depression and anxiety have been associated recently with insulin resistance and inflammatory states, factors that are relevant to the development of NASH. We hypothesized that depression and anxiety would be more prevalent in NASH patients and predict more severe histological findings on liver biopsy. METHODS: Histories of major depressive disorder (MDD) and generalized anxiety disorder (GAD) were determined using a structured interview and DSM-IV criteria in 36 NASH subjects and 36 matched controls without liver disease who had undergone cholecystectomy. Histological changes on liver biopsy in NASH subjects were age-adjusted and compared in subjects with and without psychiatric disorders. A multivariate model incorporating other potential risk factors for NASH (female sex, body mass index, waist-to-hip ratio, and presence of diabetes) was used to determine independent effects of MDD and GAD on severity of histological findings. RESULTS: NASH subjects had significantly increased lifetime rates of MDD (odds ratio [OR], 3.8; 95% confidence interval [CI], 1.4-10.2; p = .018) and GAD (OR 5.0, 95% CI, 1.7-14.9; p = .005). The onset of psychiatric illness preceded diagnosis of liver disease by 18 to 20 years. Each psychiatric disorder was associated with more severe histological features (p < .05 for each), the effect of GAD on fibrosis stage persisting in the multivariate model. CONCLUSIONS: MDD and GAD are overrepresented in NASH subjects and are associated with more advanced liver histological abnormalities. Additional investigation will be required to determine if depression and anxiety affect the development or progression of NASH and serve as modifiable risk factors.