Learning about the “nocebo effect” prevents false ADHD self-diagnosis, study shows

Mental health awareness campaigns have become a staple in universities and schools, aiming to reduce stigma and encourage treatment. A new study suggests that these well-intentioned efforts may have an unintended side effect for healthy young adults. Research published in Psychological Medicine found that learning about the signs of attention-deficit/hyperactivity disorder (ADHD) led many participants to falsely identify themselves as having the condition.

But the researchers also discovered that this spike in false self-diagnosis could be prevented. They tested a brief educational intervention designed to explain how negative expectations can influence physical and mental states. When participants received this “nocebo education” alongside the standard mental health information, they were significantly less likely to wrongly attribute a disorder to themselves.

In recent years, rates of reported mental health problems have surged among young adults in North America. Universities and advocacy groups have responded by ramping up awareness efforts to help students recognize symptoms. The goal is to ensure that those struggling receive the help they need.

There is growing concern among experts that these campaigns might be casting too wide a net. Some evidence indicates that when healthy individuals learn about the broad symptoms of a condition, they may begin to view their normal life difficulties through the lens of a medical disorder. This phenomenon is often linked to the “nocebo effect.”

The nocebo effect occurs when negative expectations lead to a worsening of symptoms or the perception of illness. In the context of mental health, a person might learn that distractibility is a sign of ADHD. Consequently, they might interpret ordinary lapses in attention as evidence of a neurological condition.

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The authors of the current study aimed to test whether this effect could be observed in a controlled setting. They also sought to develop a way to “inoculate” students against it. They hypothesized that explaining the mechanism of the nocebo effect would help students maintain a more objective view of their own experiences.

“We talk about mental health more than ever before. Especially so about ADHD,” said study author Dasha A. Sandra, a PhD student at the University of Toronto, Scarborough. “The awareness efforts are growing in schools, universities, and especially online. While we know that these can be helpful, it’s unclear if they can also be harmful by changing people’s expectations and nudging them to falsely self-diagnose or develop symptoms. And if they are, we wanted to find a way to reduce these harms without reducing the awareness itself.”

To test this, the researchers recruited 215 young adults from the University of Toronto Scarborough. A key part of the study design was the selection process. The team specifically screened for individuals who did not meet the criteria for ADHD.

They used a validated screening tool and excluded anyone who scored above a certain threshold. This ensured the sample consisted of participants who were highly unlikely to be true cases of the disorder. The researchers also excluded anyone with a prior history of psychiatric or neurological diagnoses.

The participants were invited to the laboratory under the guise of evaluating health workshops. They were randomly assigned to one of three groups. The first group attended a standard ADHD awareness workshop.

This session presented statistics on the disorder and described various symptoms. It included a video of an advocate describing her personal experiences. The workshop concluded with a writing exercise where participants reflected on whether they related to the symptoms.

The second group received the same ADHD awareness material but with an added component. Before the main presentation, they received a ten-minute lesson on the nocebo effect. This brief session explained how learning about symptoms can sometimes cause people to misinterpret normal experiences as signs of illness.

The third group served as a control. These participants attended a workshop about sleep and dreaming. They learned about sleep hygiene and theories regarding why humans dream.

Participants completed surveys immediately after the workshop and again one week later. These surveys measured their tendency to self-diagnose with ADHD. The researchers also measured the participants’ self-reported symptom levels.

The results revealed a substantial increase in false self-diagnosis among those who received only the standard ADHD awareness training. Before the workshop, about 30 percent of this group rated themselves as having high levels of identification with the disorder. Immediately after the workshop, that number nearly doubled to 58 percent.

“The sheer magnitude of the effect was quite surprising,” Sandra told PsyPost. “This was just one half-hour workshop delivered once, whereas normally people get mental health awareness repeatedly from many channels in different ways, for example at home, in school, from friends, online. So we had modest expectations. But even this one workshop was clearly enough to change people’s self-diagnosis.”

This elevated rate of self-diagnosis persisted over time. One week after the session, 52 percent of the participants in the standard awareness group still believed they likely had ADHD. This occurred even though their actual reported symptom severity did not change significantly.

The group that received the nocebo education showed a different pattern. They did experience a rise in self-diagnosis immediately after the workshop, but it was only half as large as the increase seen in the standard group. More importantly, this increase did not last.

By the one-week follow-up, the self-diagnosis rates in the nocebo education group had returned to levels comparable to the control group. About 35 percent of them endorsed a high self-diagnosis score, which was statistically indistinguishable from the control group’s 30 percent. The brief intervention effectively neutralized the long-term impact of the awareness materials.

“In practical terms, the effect was quite large,” Sandra said. “The number of people who had a high self-diagnosis rating went from 30% before the ADHD workshop to almost 60% immediately after, and then stayed over 50% a week later. This didn’t happen in the control group. When we combined mental health awareness with the intervention, though, this false self-diagnosis effect was gone after one week.”

These findings provide evidence that healthy young adults are highly susceptible to suggestion regarding mental health. A single thirty-minute session was enough to convince a majority of participants that they had a disorder they had previously screened negative for. This suggests that the current approach to mental health awareness may need adjustment.

The study implies that context is vital when presenting medical information to the public. Without guidance on how to interpret symptoms, individuals may pathologize normal variations in human behavior. The “nocebo education” functioned like a vaccine, offering protection against misinformation while still allowing students to learn about the condition.

“If young people learn about a mental disorder, they may feel like they have it even if they don’t, and then self-diagnose with it,” Sandra explained. “But if you use our intervention to effectively tell them ‘you might think that you have these, but you probably don’t, and that’s normal,’ — that removes the effect.”

The researchers noted that the intervention was simple and scalable. It took only ten minutes to deliver. This makes it a feasible addition to school curriculums or university orientation programs.

There are some limitations to the study that should be considered. The research focused on university students, who may be more responsive to educational interventions than the general public. The study also relied on self-reported beliefs rather than clinical interviews or behavioral outcomes.

It is not known whether the participants who self-diagnosed would have gone on to seek medical treatment or request academic accommodations. Future research is needed to track these real-world behavioral consequences. The researchers also suggest investigating whether this intervention works in online environments, where many young people consume mental health content.

The study highlights a disconnect between self-perception and actual symptoms. Participants in the standard awareness group believed they had the disorder, yet their scores on a symptom checklist did not increase to match that belief. This indicates that the workshop changed their identity or self-concept rather than their actual experience of impairment.

This phenomenon is particularly relevant in the age of social media. Platforms like TikTok and Instagram are filled with content that relates everyday struggles to psychiatric diagnoses. The study suggests this content could be leading large numbers of people to adopt diagnoses that do not fit them.

But the authors emphasize that the goal is not to stop mental health awareness. Recognizing legitimate disorders is essential for those who need support. The challenge is to balance awareness with accuracy.

“This work can be easily misinterpreted as evidence of the fact that ‘all diagnoses are sham,’ ‘we should not believe young people,’ or ‘we should get rid of all mental health awareness.’ That is not the point of our work at all,” Sandra said. “We believe that mental health awareness has an important place, that people’s distress is real. And at the same time, our work shows that we need to be careful about how we speak about mental health, so that we don’t mistakenly turn difficult life experiences into a psychiatric diagnosis.”

By teaching people to understand the difference between normal distress and clinical disorder, educators can prevent unnecessary anxiety. The inclusion of nocebo education appears to be a promising method for achieving this balance. It allows for the dissemination of health information while minimizing the risk of “medical student syndrome” among the general population.

“We made our intervention publicly available so that universities and schools could adapt it to their own awareness workshops,” Sandra said. “It can be found here: https://www.dashasandra.com/strategies/.”

Looking forward, “we have two main directions,” she added. “First, understanding what factors make people falsely self-diagnose or develop worse symptoms in these situations; and second, testing if our intervention can reduce the false self-diagnosis and improve functioning for people who have already self-diagnosed.”

The study, “Inform and do no harm: Nocebo education reduces false self-diagnosis caused by mental health awareness,” was authored by Dasha A. Sandra, Zindel Segal, Sanaa Majoo, Anastasia Sistanis, Matthew J. Burke, and Michael Inzlicht.