OBJECTIVES: To identify through retrospective pharmacy claims analysis the relationship between generalized anxiety disorder (GAD) and peptic ulcer disease (PUD). METHODS: A total of 3.7 million continuously eligible participants (age 18-64) in Caremark's pharmacy claims database were retrospectively analyzed for treatment of GAD and/or PUD from January 2001 through December 2001. Participants were categorized as having either GAD or PUD when a pharmacy-targeting algorithm was triggered for respective disease states during the time period. Multivariate logistic regression analysis was used to determine the relationship between GAD and PUD, controlling for differences in age, gender and income. Multivariate logistic regression analysis was also used to determine the relationship between GAD and the presence of chronic conditions, excluding allergic rhinitis. RESULTS: Participants being treated for GAD were associated with an increased risk of being treated for PUD (OR: 2.18, 95% CI: 2.05-2.33; p<0.0001). Participants suffering from chronic conditions were associated with an increased risk of being treated for GAD (OR: 1.99, 95% CI: 1.98-2.00; p<0.0001). Participants being treated for two or more chronic disease states were associated with an increased risk of being treated for GAD; 2 chronic conditions (N=437,637, OR: 2.49, 95% CI:2.46-2.51; p<0.0001); 3 chronic conditions (N=126,624,odds ratio 4.06, 95% CI=4.00-4.13, p<0.0001); 4 or more chronic conditions (N=34,411, OR: 6.30, 95% CI: 6.14-6.48, p<0.0001). CONCLUSION: The relationship between GAD and PUD is consistent with previously published findings (Goodwin et.al. 2002). However, additional analysis presented here shows that the presence of two or more chronic condition increases the risk for GAD. Therefore, the correlation initially identified between GAD and PUD may be indicative of the presence of an underlying chronic condition causing an anxiety disorder. This evidence suggests that GAD should be considered as a comorbidity of chronic disease and should be incorporated into management strategies.