Placebo effects in caregivers may change behavior of children with ADHD

Jun 29 2009

Stimulant medications, such as Ritalin and Adderall, are the accepted treatment to stem hyperactivity in children with attention deficit-hyperactive disorder (ADHD) and improve their behavior.

Now a recent review of research by University at Buffalo pediatric psychologists suggests that such medication, or the assumption of medication, may produce a placebo effect -- not in the children, but in their teachers, parents or other adults who evaluate them.

A placebo effect is a positive change in symptoms or behavior after a patient receives a "fake" medication or procedure; in other words, the belief can become the medicine. In this case, the review suggested that when caregivers believed their ADHD patients were receiving ADHD medication, they tended to view those children more favorably and treat them more positively, whether or not medication was actually involved.

"The act of administering medication, or thinking a child has received medication, may induce positive expectancies in parents and teachers about the effects of that medication, which may, in turn, influence how parents and teachers evaluate and behave toward children with ADHD," said UB researcher Daniel A. Waschbusch, Ph.D., lead author of the review.

"We speculate that the perception that a child is receiving ADHD medication may bring about a shift in attitude in a teacher or caregiver. They may have a more positive view of the child, which could create a better relationship. They may praise the child more, which may induce better behavior."

Such a placebo effect in caregivers could have both good and not-so-good results, Waschbusch added. "If teachers treat children more positively if they think they are on medication, that is a good thing. But if the child's medication is increased because caregivers think it is effective, that may not be a good thing."

Waschbusch is an associate professor of psychology in the Department of Pediatrics at UB and conducts his research in UB's Center for Children and Families. The study was published in a recent issue of the Journal of Development & Behavioral Pediatrics.

Waschbusch and colleagues reviewed existing studies that evaluated whether placebos produce significant changes in children with ADHD and assessed four possible ways placebos could have an effect:

• Through the child's expectations of a change -- The analysis showed that any change in children's behavior was a direct result of the medication, not the expectation.
• By producing changes in how caregivers perceive children with ADHD when they think they are on medication -- The researchers determined the studies suggested that this may be a viable mechanism for the placebo effect.
• By producing changes in how caregivers behave toward children with ADHD who they think are on medication, which in turn, could produce changes in the child -- The analysis supported this hypothesis.
• Placebos may operate through classical conditioning. "For example," explained Waschbusch, "if a parent routinely gives their child active medication in pill form and then sees their child's behavior immediately improve, they will likely learn to connect administering a pill with improved child behavior. This learned connection could then be generalized to administering a placebo pill."

Waschbusch said the next step in this investigation could be a study that observes parents and children interacting under three different conditions: after children received a pill with real medication, after children received a pill with fake medication (a placebo) and after children didn't receive any pill.

"Comparing these conditions would provide information about the effects of actual medication relative to just getting a placebo," he said.

William E. Pelham, Jr., Ph.D., and James Waxmonsky, M.D., from UB, and Charlotte Johnston, Ph.D., from the University of British Columbia, are co-authors on the study.

When conducting this review, the authors were supported partially by grants from institutes within the U.S. Department of Health and Human Services, the U.S. Department of Education and the Eli Lilly Corporation.

The University at Buffalo is a premier research-intensive public university, a flagship institution in the State University of New York system and its largest and most comprehensive campus. UB's more than 28,000 students pursue their academic interests through more than 300 undergraduate, graduate and professional degree programs. Founded in 1846, the University at Buffalo is a member of the Association of American Universities.