Objective: To evaluate a 3-week, randomized, double-blind, methylphenidate placebo-controlled trial (MPT) in routine practice for children with attention-deficit disorder.
Patients and methods: School-aged children with attention-deficit/hyperactivity disorder (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria) who enrolled an "N of 1" trial at a pediatric tertiary care center were eligible. Families (n = 50) with a child eligible for the MPT were given 3 bottles of identical capsules. The capsules contained, in random order: placebo of the prescribed dose of methylphenidate (Ritalin) hydrochloride (0.3 mg/kg or 0.6 mg/kg). Families gave the child 1 capsule at 8 AM and 1 capsule at noon. The family, teacher, and physician were blinded for the order of medication. Conners questionnaires (Conners Parent Questionnaire and Conners Teacher Questionnaire) and written comments were completed by parents and teachers at baseline and at the end of each week. Once MPT results were known and following discussion with the physician, families decided whether to continue methylphenidate therapy. Families were interviewed by telephone 14 to 21 months after the MPT.
Results: Forty-three (86%) of the 50 eligible children (mean age, 129 months) were contacted. No family found the MPT difficult, but 6 trials were incomplete, usually because of side effects. All families used the MPT to decide if methylphenidate was the correct treatment choice for their child and 68% (34 of 50 families) used the results exclusively. The remaining 16 families believed the MPT was helpful. Overall, 31 (72%) of the 43 children had a good response to methylphenidate treatment--20 (47%) continued to use it for longer than 12 months and 8 (26%) for 2 to 12 months; 3 responders chose not to use it after the MPT. Nine of the 43 families chose not to use methylphenidate treatment; however, all indicated that participating in the MPT helped them to make that decision. In follow-up interviews, the same proportion of methylphenidate users and nonusers reported improvement in many areas of function including significantly less time spent doing homework. Users reported reduced aggression (P<.001) and fewer discipline problems (P<.01) compared with nonusers.
Conclusions: An "N of 1" MPT was easily performed and permitted families to decide whether to use methylphenidate for long-term treatment of attention-deficit disorder or attention-deficit/hyperactivity disorder. Regardless of methylphenidate use or lack of use, the condition of all of these children was improved at follow-up.