Behavioral and cognitive effects of methylxanthines. A meta-analysis of theophylline and caffeine
M. A. Stein, M. Krasowski, B. L. Leventhal, W. Phillips and B. G. Bender
Section of Child and Adolescent Psychiatry, Department of Psychiatry, University of Chicago (Ill), USA.
BACKGROUND: Theophylline has been extensively studied as a treatment of
asthma. However, some studies have suggested that theophylline may
precipitate 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 disorder.
OBJECTIVE: To present a meta-analysis of research on the behavioral and
cognitive effects of methylxanthines in children. METHODS: The
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 controlled 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 externalizing behavior
for both methylxanthines. CONCLUSIONS: There is little evidence to suggest
that methylxanthines have adverse cognitive or behavioral effects on
children. Questions remain with regard to the identification and
determinants of either responsive or sensitive subgroups, dose-response
relationships, and the effects of parent-teacher expectancies on behavioral
ratings.
