Research consistently demonstrates that prison inmates are more likely than the general population to suffer from both mental disorders and substance abuse. The current study explored the relationship between diagnoses of mental disorders and maladaptive substance use among state and federal prison inmates. Linear regression analysis was used to ascertain the prevalence of comorbidity of substance abuse and mental disorder, and multiple models were constructed to determine the direction of relationship between the two disorders. Overall, mental disorders and substance use were positively related within the sample, though mixed conclusions were drawn regarding the exact nature of their relationship. Recommendations for future study and improvements to the specificity of mental disorders and substance use measures are made
