Effect size was greater in open-label than placebo-controlled studies, suggesting the influence of certainty on treatment outcomes.
When developing clinical trials in patients with severe cognitive impairment, researchers sometimes view a placebo arm as unnecessary (except to control for spontaneous responses), as the placebo effect relies on patients' expectations about treatment. To determine the placebo component of treatment responses in intellectually disabled patients, investigators conducted a meta-analysis of 17 open-label versus 22 placebo-controlled trials of various medications and supplements in a total of 982 participants with fragile X, Down, Prader-Willi, and Williams syndromes.
Treatment response was defined as the difference in outcomes before and after treatment in each arm. Overall effect sizes for open-label versus placebo-controlled trials were deter…
Reviewing Author
DisclosuresRoyaltiesTextbook of Traumatic Brain Injury, 2nd and 3rd editions
Editorial BoardsUpToDate; Journal of Neuropsychiatry and Clinical Neuroscience
Leadership Positions in Professional SocietiesNorth American Brain Injury Association (Board Member); National Institute on Disability, Independent Living, and Rehabilitation Research (Chair of Data Monitoring Safety Board for study of donepezil on cognition after traumatic brain injury)
DisclosuresRoyaltiesTextbook of Traumatic Brain Injury, 2nd and 3rd editions
Editorial BoardsUpToDate; Journal of Neuropsychiatry and Clinical Neuroscience
Leadership Positions in Professional SocietiesNorth American Brain Injury Association (Board Member); National Institute on Disability, Independent Living, and Rehabilitation Research (Chair of Data Monitoring Safety Board for study of donepezil on cognition after traumatic brain injury)