BEHAVIORAL AND COGNITIVE EFFECTS OF METHYLXANTHINES - A METAANALYSIS OF THEOPHYLLINE AND CAFFEINE

Background: Theophylline has been extensively studied as a treatment o f asthma. However, some studies have suggested that theophylline may p recipitate adverse behavioral and cognitive effects on children. Other reports have evaluated the effects of caffeine, another commonly used methylxanthine, as a treatment of attention-deficit hyperactivity dis order. Objective: To present a meta-analysis of research on the behavi oral and cognitive effects of methylxanthines in children. Methods: Th e meta-analyses were conducted on 12 studies of theophylline and nine studies of caffeine that met inclusion criteria. Results: In contrast to popular beliefs and earlier scientific reports, meta-analyses of co ntrolled studies did not indicate that either theophylline or caffeine resulted in significant deleterious effects on cognition or behavior. In fact, there was a small, positive effect on parental report of ext ernalizing behavior for both methylxanthines. Conclusions: There is li ttle evidence to suggest that methylxanthines have adverse cognitive o r behavioral effects on children. Questions remain with regard to the identification and determinants of either responsive or sensitive subg roups, dose-response relationships, and the effects of parent-teacher expectancies on behavioral ratings.