The effect of stimulants on overt (physical assault or temper outburst) and covert (cheating, lying, stealing, vandalism) aggression-related behaviors in children with ADHD was determined by literature meta-analysis at the University of Massachusetts Medical School and Northeastern University, Boston. A review of 28 published reports, 1970-2001, revealed 28 and 7 independent effects of overt and covert aggression, respectively. Stimulants had significant, moderate to large effects on aggression-related behaviors, separate from and of equal magnitude to their effects on symptoms of ADHD. Girls responded equally as well as boys. Dose had no significant relation to effect size, but duration of treatment had a significant positive correlation. 
COMMENT. Treatment with stimulants is effective in the control of aggressive-related behaviors in children with ADHD and co-morbid conduct disorders.
Psychiatric comorbidity in preschool children with ADHD. In a study of 165 patients aged 4 to 6 years compared to 381 aged 7 to 9 years, the preschoolers had similar substantial rates of impairment in school, social, and overall functioning to those in school-age children . These findings support an early intervention treatment program for preschoolers presenting with ADHD.