A Clinical Trials Evaluation of a Double-Blinded Protocol to Assess the Therapeutic Effectiveness of Stimulant Medication Prescribed for Children Diagnosed ADHD
Date of Award
Doctor of Philosophy
Dr. Galen Alessi
Dr. Kevin Armstrong
Dr. Wayne Fuqua
Dr. Dennis Simpson
This clinical trials investigation developed and evaluated a protocol for determining the therapeutic effectiveness of medication prescribed for children diagnosed ADHD. The protocol included two separate baseline periods of two week durations, each of which were followed by four randomly assigned probes of one week duration, consisting either of Methylphenidate or placebo capsules. Baseline probes were unblinded, but medication and placebo probe trials were double-blinded. Therapeutic effect, expectancies, and integrity of the double-blind control were assessed through a battery of rating scales and forms completed by the parent, teacher and child at the end of each protocol week, including baseline weeks. Multiple samples of systematic classroom observations also were collected for the child and a yoked peer to compare with data derived from the rating forms.
Symptomatic rating forms and in-class observation data were not always in agreement regarding Ritalin's therapeutic effectiveness for a particular child. There were low and even negative correlations between parent and teacher ratings as well as between two teachers of the same child. Behavioral observation data were more consistent and reliable and suggested children were on-task 6.2% more during blinded Ritalin probes than during placebo probes. Whether these small observed differences would be clinically significant in the classroom or at home is hard to determine.
Parents and teachers did not "break the code" for the double-blind control: most often they indicated they did not know which condition was in effect during any given week. In addition, neither parents nor teachers varied their weekly ratings in a way consistent with their expectations about which probe condition (medication or placebo) was in effect Expectations appeared to influence symptomatic ratings because for parents there was a 36% and for teachers a 21% differerence in favor of unblinded over blinded Ritalin conditions on the Conners Rating Scales.
Children did not rate themselves more externally after the protocol and instead rated themselves in a more internal direction. Parent and Teacher ratings on symptomatic rating scales did not appear to be contaminated by mood or marital/job happiness.
Basing medication decisions on more systematically collected and analyzed data from drug evaluation protocols using multiple sources, and double-blind placebo controlled probes, may reduce the unnecessary use of medications with ADHD children.
Thompson, Ann V., "A Clinical Trials Evaluation of a Double-Blinded Protocol to Assess the Therapeutic Effectiveness of Stimulant Medication Prescribed for Children Diagnosed ADHD" (1994). Dissertations. 1852.