Video-assisted behavior observation as a tool for methylphenidate dose finding in ADHD: longer term outcome

Introduction: A standardized procedure of video-assisted observation of the variability of the smile allows the determination of an optimal regulation state in ADHD-children and adolescents treated with methylphenidate (MPH). Regulation worsens with changes of 2.5 mg MPH (1). A continuous performance test which includes head movements, reaction time, and accuracy (Qb-Test) follows the same curvilinear course when single dose of MPH is slowly augmented and passes the turning point which we denominate “optimal.” Use of this MPH dose improves highly significant all DSM-IV characteristics of ADHD.

Objectives: To test if improvements last for a long time and retesting shows similar results.

Methods: A sample of 12 ADHD patients (6 to 12-year-olds, 2 girls and 10 boys) was retested after 10 months. After 8 months Du Paul's ADHD rating scale was filled out by parents.

Results: Of the total samples 9 (8 boys and 1 girl) could be reexamined. In 8 of 9 patients, the optimal dose was the same. In one boy, video-assisted observation suggested a 2.5 mg lower dose. Qb-Test parameters showed again the same shape of the dose-dependent curve as video observation, both in the first and the repeated assessment. Student t-test for paired samples shows significant differences from “without medication” to “optimal” dose. Improvement in ADHD rating scale is highly significant and remains stable for 8 more months.

Conclusions: Although limited by the small sample size, results indicate that involuntary behavior features coincide with reaction time measures and help find a good MPH dose which keeps stable for a long time. The procedure offers stable improvements in behavior ratings and has proved to be a useful tool in our daily practice.