The relationship among caffeine consumption, anxiety, depression, and caffeine expectancies

Current literature on the relationship between anxiety and caffeine consumption is mixed; some studies suggest that they are positively correlated, while others report a negative correlation or no relationship. This study evaluated the relationship between self-reported anxiety and caffeine use, using more precise measures of anxiety and caffeine consumption. In addition, the relationship between caffeine use and anxiety sensitivity and caffeine use and depression were also evaluated. Expectancies for the effects of caffeine were evaluated as a potential moderator of the relationship between caffeine and anxiety-related variables and caffeine and depression. Caffeine use was significantly positively related to both anxiety and depression, while no significant relationship was found between caffeine consumption and anxiety sensitivity. Regression analyses indicated that caffeine expectancies function as a moderator in the relationships between caffeine use and anxiety and caffeine use and depression, but not in the relationship between caffeine use and anxiety sensitivity.