Expectancy effects of placebo neurofeedback in ADHD treatment seekers: A neuropsychological investigation.
Neuropsychology. 2020 Jul 30;:
Authors: Lee GJ, Suhr JA
OBJECTIVE: Though there is evidence to suggest that expectancies can impact outcomes of various medical and psychological treatments, little is known about the role of expectancy effects in neurocognitive interventions, such as neurofeedback for attention-deficit/hyperactivity disorder (ADHD). The present study investigated the effects of treatment expectancies on ADHD symptom report and neuropsychological performance by using an expectancy manipulation in the context of placebo neurofeedback.
METHOD: Eighty-five young adults seeking treatment for ADHD were administered 1 session of placebo neurofeedback and randomly assigned to positive or negative expectancy groups. Primary outcome measures include ADHD symptom self-report questionnaires and neuropsychological tests.
RESULTS: Consistent with hypotheses, participants in the positive expectancy group who received positive false feedback reported fewer ADHD symptoms at postfeedback (p < .001, ηp² = .41), whereas participants in the negative expectancy group who received negative false feedback reported more symptoms at postfeedback (p = .01, ηp² = .15). As expected, individuals who received positive expectancies also significantly improved their performance on a working memory test (p = .002, ηp² = .22); no other neuropsychological test performance was impacted by expectancies. Beliefs about neurofeedback effectiveness did not moderate or mediate expectancy effects.
CONCLUSION: Results indicate that treatment expectancies impact ADHD symptom report and some neuropsychological test performance. Therefore, expectancy effects should be considered in the evaluation of outcomes for neurocognitive interventions, such as neurofeedback for ADHD. (PsycInfo Database Record (c) 2020 APA, all rights reserved).
PMID: 32730049 [PubMed – as supplied by publisher]