In alcohol-dependent drinkers, what does the presence of nicotine dependence tell us about psychiatric and addictive disorders comorbidity?

AIM: To examine the pattern of psychiatric comorbidity associated with nicotine dependence among alcohol-dependent respondents in the general population.
METHODS: Drawn from a US national survey of 43,000 adults The (National Epidemiologic Survey on Alcohol and Related Conditions) who took part in a face-to-face interview, data were examined on the 4782 subjects with lifetime alcohol dependence, and comparisons were made between those with and those without nicotine dependence.
RESULTS: Nicotine dependence was reported by 48% of the alcohol-dependent respondents. They reported higher lifetime rates of panic disorder, specific and social phobia, generalized anxiety disorder, major depressive episode, manic disorder, suicide attempt, antisocial personality disorder and all addictive disorders than those without nicotine dependence. After controlling for the effects of any psychiatric and addictive disorder, alcohol-dependent subjects with nicotine dependence were more than twice as likely as non-nicotine-dependent, alcohol-dependent subjects to have at least one other lifetime addiction diagnosis (adjusted odds ratio 2.36; 95% confidence interval 2.07-2.68).
CONCLUSIONS: Nicotine dependence represents a general marker of psychiatric comorbidity, particularly of addictive comorbidity. It may be used as a screening measure for psychiatric diagnoses in clinical practice as well as in future trials.