Among Axis I disorders, alcohol abuse decreased the probability of treatment of drug abuse, whereas alcohol dependence decreased the probability of treatment of drug abuse and dependence. Complementary analyses indicated that among individuals with drug dependence, the adjusted hazard ratio for treatment of drug dependence was 1.04 (95% CI: 0.79, 1.36) among individuals who did not seek treatment for alcohol dependence and 0.58 (95% CI: 0.42, 0.80) among individuals with treated alcohol dependence. Dysthymia increased the probability of treatment of alcohol dependence and drug abuse, comorbid major depressive disorder was associated with greater probability of treatment of alcohol abuse and comorbid bipolar disorder was associated with increased probability of treatment of alcohol abuse and dependence. Comorbid-specific phobia was associated with a lower probability of treatment of alcohol abuse and comorbid pathological gambling with a lower probability of treatment of drug abuse, whereas comorbid PTSD increased the probability of treatment of alcohol dependence.
