The therapeutic effectiveness of methylphenidate (MPH) (0.3 mg/kg) in attention-deficit hyperactivity disorder (ADHD) was compared during childhood (ages 8 to 11 years) and adolescence (ages 12 to 14.5 years) in a retrospective follow-up study of 16 patients who had completed double-blind, placebo-controlled, crossover trials during two separate summer treatment programs at the Western Psychiatric Institute, University of Pittsburgh Medical Center, PA. Of 12 dependent variables, including objective measures of academic performance and social behavior, and counselor and teacher ratings, only 3 showed significant changes in the effect size of MPH from childhood to adolescence. Stimulant medication was equally effective in ADHD during childhood and adolescence, if environmental factors and activities remained constant. 
COMMENT. Stimulant therapy for ADHD is equally effective for children and adolescents. The dose of methylphenidate should not automatically be increased in accordance with age and weight gains. ADHD patients who develop worsening of symptoms in high school should receive psychosocial counselling before considering an increase in dose of stimulant.
Diagnostic continuity between child and adolescent ADHD was documented in a study of a longitudinal clinical sample at the Pediatric Psychopharmacology Unit, Massachusetts General Hospital, Boston . Patterns of psychosocial adversity and comorbidity with conduct, mood, and anxiety disorders were almost identical. Substance abuse differed in the two age groups, but was independent of ADHD.
Approach to treatment of ADHD in adolescents with substance use disorders and conduct disorder was reviewed from the Addiction Research and Treatment Services Program, University of Colorado School of Medicine, Denver . In this center, adolescents with ADHD and comorbid substance abuse and conduct disorders are treated with pemoline or buproprion, which have a lower abuse potential than psychostimulants such as dextroamphetamine and methylphenidate. Tricyclic antidepressants are considered too dangerous for use in impulsive youths, with risk of illicit drug interaction and high incidence of death with overdose. A multimodal treatment approach and urine toxicology monitoring are recommended.
Conduct disorder in children in the UK is reviewed from the Department of Child and Adolescent Psychiatry, Institute of Psychiatry, London . Aggressive behavior occurs in 10% of children in an urban population. The majority of juvenile delinquents have had conduct disorders at age 7. The main cause of conduct problems is linked to harsh, inconsistent parenting, but hyperactivity (ADHD) and learning difficulties contribute. Programs to improve parenting and school interventions to reduce antisocial behavior may be effective in children under 10 years, but are less successful in adolescence.
Fetal cocaine exposure and brain abnormalities, one presumptive cause of ADHD, was studied by cranial ultrasound of 134 cocaine-exposed and 132 control newborns, at the University of Florida, Gainesville, FL . Subependymal, third ventricle, and choroid plexus cysts, and enlarged ventricles were identified in 17 cocaine-exposed infants and in 10 controls, but the difference was not significant. The incidence of cerebral abnormalities was lower than that previously reported. Temporal lobe arachnoid cysts have been linked to some cases of ADHD.