Background: The strong comorbidity between substance use disorders (SUDs) and mood and anxiety disorders has been well documented. In view of lack of research findings addressing the co-occurrence of SUDs and mood and anxiety disorders, this study examined the pattern of comorbidity of alcohol use disorders (AUDs) and nicotine dependence (ND) between 2 culturally diverse countries, the United States and South Korea.
Methods: Using the nationally representative samples of the U.S. and Korean general populations, we directly compared rates and comorbidity patterns of AUDs, ND, and mood and anxiety disorders between the 2 countries. We further examined the rates and the comorbidity pattern among individuals with AUDs who sought treatment in the last 12 months. Twelve-month prevalence rates were derived to estimate country differentials, and odds ratios (ORs) and 95% confidence intervals were estimated to measure the strength of comorbid associations while adjusting for all sociodemographic characteristics in multivariate logistic models specific to each country.
Results: The 12-month prevalence rates of AUDs, ND, and any mood disorder and any anxiety disorder were 9.7, 14.4, 9.5, and 11.9% among Americans, whereas the corresponding rates were 7.1, 6.6, 2.0, and 5.2% among Koreans. These rates were significantly greater (except for any AUD) among Americans than among their Korean counterparts. With respect to comorbidity, both countries showed comparable patterns that the prevalence rates of mood and anxiety disorders were consistently the highest among persons with alcohol dependence (AD). Also, a disparate pattern was observed in Korea that the prevalence rates of mood and anxiety disorders were generally lower among individuals with ND than among those with alcohol abuse and AD. Furthermore, despite significantly greater prevalence of AD in Korea (5.1%) than in the United States (4.4%), alcohol-dependent Americans were 4 times (OR = 3.93) more likely to seek treatment compared to their Korean counterparts.
Conclusions: Our results indicated that the prevalence of AD in Korea was substantially greater than that in both Western and other Asian countries, suggesting a maladaptive pattern of alcohol use in Korea, which is different from the general use pattern of other East Asian countries. The low rate of treatment utilization among Koreans might be attributable to perceived social stigma toward SUDs or mental health problems despite the fact that the Korean government offers national health insurance.