Inform and Do No Harm: Learning About the Nocebo Effect Reduces Unintended Harms of Mental Health Awareness

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. Yet, there are no validated approaches to avoid these potential harms without simply reducing the awareness efforts. Thus, we developed a multi-faceted intervention, nocebo education, to reduce these harms; the intervention is based on the principles of the nocebo effect, i.e., the effect of negative expectations causing symptom misattribution and worsening. We tested whether this intervention could mitigate false self-diagnosis and symptom worsening from ADHD awareness. In a double-blind randomised controlled trial with a week-long follow-up (NCT06638411), 215 healthy young adults (77% women) were randomised to participate in a 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 one-week later (self-diagnosis and symptoms). ADHD group reported substantially higher self-diagnosis scores immediately (𝛽_standardised= 0.80) and one week after the workshop (𝛽 = 0.50) 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) and eliminated it at follow-up. 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 eliminating this harm. Nocebo education is a promising adjunct for balanced awareness efforts that could be applied in various contexts.