Objective: Cross-sectional studies show a robust association between anxiety disorders and alcohol use disorders (comorbidity); however, this methodology does not allow for the testing of causal models. The authors attempted to overcome this limitation by examining comorbid relationships prospectively.
Method: Male and female college students were assessed as freshmen (year 1), and then again at years 4 and 7, for selected 12-month anxiety disorders (generalized anxiety disorder, agoraphobia, and social phobia or panic) diagnosed according to the National Institute of Mental Health Diagnostic Interview Schedule (DIS) and DSM-III and for 12-month DIS/DSM-III alcohol use disorders (alcohol dependence alone and alcohol abuse or dependence).
Results: Cross-sectionally, the odds of having either an anxiety disorder or an alcohol use disorder were two- to fivefold greater when the other condition was present. Prospectively, the odds of developing a new alcohol dependence diagnosis at year 7 increased from 3.5 to five times for those diagnosed with an anxiety disorder at years 1 or 4. Conversely, the odds of developing a new anxiety disorder at year 7 increased by about four times for those diagnosed with alcohol dependence at years 1 or 4. When alcohol abuse and dependence were combined, the pattern of findings was similar, albeit weaker. Multivariate path models provide similar results and highlight the reciprocal influence of alcohol use disorders and anxiety disorders.
Conclusions: Alcohol use disorders (especially alcohol dependence) and anxiety disorders demonstrate a reciprocal causal relationship over time, with anxiety disorders leading to alcohol dependence and vice versa.