Dr Dennis Cantwell, a world renown expert on ADHD, died April 14, 1997. In an article submitted from the UCLA Neuropsychiatric Institute in March 1997, as guest editor of a special section on ADHD, Dr Cantwell outlines his model in 8 phases of scientific study as follows: clinical diagnostic criteria, demographic, psychosocial, biological, family genetic, and family environmental factors, natural history, and management with psychostimulant medication and psychosocial methods of intervention. Articles by other investigators that follow this introduction include comorbidity with juvenile-onset mania (ADHD may signal a very early onset of bipolar disorder); two new subclassifications (1. ADHD plus comorbid anxiety disorder may predict a lesser response to MPH; 2) ADHD plus conduct disorder and aggressive behavior predicts a more negative outcome); gender differences (ADHD girls have greater intellectual impairment, lower levels of hyperactivity, and lower rates of aggression); benefits of parent-assisted social skills training (ADHD-peer rejection may be benefited by a combination of child social skills training, training for the parents, and stimulant medication). 
COMMENT. Future research suggested by the articles in this excellent review include: 1. The relation of MPH response to outcome over time; 2. different diagnostic criteria based on gender and age; 3. criteria for adult ADD; 4. genetic and biological markers; and 5. long-term efficacy of stimulant treatment. We should also add the need for research on adverse effects of stimulant therapy, including medication-induced seizures.