Inform and do no harm: Nocebo education reduces false self-diagnosis caused by mental health awareness

Background Mental health awareness efforts are increasing, especially for ADHD. There is growing evidence that such efforts may also cause unnecessary self-diagnosis and worsening symptoms for some disorders; however, there are no validated approaches to avoid these potential harms without reducing the awareness efforts themselves. We developed a multifaceted intervention, called nocebo education. The intervention was based on the principles of the nocebo effect, where negative expectations may cause symptom misattribution and worsening. We tested whether teaching about the nocebo effect could mitigate the potential false self-diagnosis and symptom worsening from ADHD awareness. Methods In a double-blind randomized controlled trial with a week-long follow-up (NCT06638411), 215 healthy young adults (77% women) were randomized to participate in a group workshop on either ADHD awareness, ADHD combined with nocebo education, or control (sleep). We measured changes in self-diagnosis and ADHD symptoms immediately after the workshop (self-diagnosis), and 1-week later (self-diagnosis and symptoms). Results ADHD group reported substantially higher self-diagnosis scores immediately (βstandardised=0.80\;[0.58,1.02],p<.001 ) and 1 week after the workshop (β =0.50\;[0.28,0.72],p<.001 ) compared to controls. These effects persisted despite no changes in reported symptoms. Nocebo education halved the false self-diagnosis scores immediately after the workshop ( β =0.45\;[0.23,0.67],p<.001 ) and eliminated the false self-diagnosis entirely at follow-up (β =0.16\;[-0.06,0.38],p=.08 ). Conclusions We show that being exposed to ADHD awareness reliably increases false self-diagnosis among healthy young adults for at least one week; a brief nocebo education intervention is efficacious in substantially reducing and later eliminating it. Nocebo education is a promising adjunct for balanced awareness efforts that could be applied in various contexts.