An Overdiagnosis Epidemic Is Harming Patients’ Mental Health

However, what has happened now is that we have a massive increase in autism, and it is not having the downstream effect of making children better. We should be seeing a slightly happier population, but all we’re seeing is worse mental health. We did something well-intentioned but there’s no evidence that it’s working.

The reason it’s not working is because when you get to the very mild end of a spectrum of behavioral or learning problems, you have a balancing act between the benefit of being diagnosed along with the help you can get, and the drawbacks of being diagnosed, which is telling a child that they’ve got an abnormal brain. What does that do to a child’s belief in themselves? How does it stigmatize them? How does it affect their identity formation? We thought it would be helpful to tell children this, but the statistics and the outcome is suggesting it isn’t helpful.

You’re also worried about another aspect of diagnostics, which is overdetection. One example you give in the book relates to modern cancer screening programs that detect the disease at earlier and milder stages. But so far there’s little evidence that these are actually beneficial to patients.

Every cancer screening program will lead to some people getting treatment when they didn’t need to be treated. That will always be the case. What we’re desperately wrangling with is that we want to make sure we keep the number of overdiagnosed people down and the number of people who need the treatment up. However, the more sensitive you make those tests, the more overdiagnosed people you will have. I read in a Cochrane review that if you screen 2,000 women, you save one life, and you over treat somewhere between 10 or 20 women. You’re always overtreating way more people than lives you’re actually saving. So the suggestion that we should do even more of these tests before we’ve perfected the ones we have does not make sense to me.

I do multiple brain scans a week and so many of them show incidental findings. Even though I’m a neurologist and I see brain scans all the time, I don’t know what to make of half of them. We just don’t yet know how to properly interpret these scans. We need to pay more attention to detecting symptomatic disease early, rather than trying to detect asymptomatic diseases that may never progress.

In some cancers—prostate cancer, for instance—patients can opt for watchful waiting rather than treatment. Should this be the norm for early detection?

If you’re going to go for screening—and I don’t want people not to go for the suggested screenings—you do need to understand the uncertainties and realize you don’t have to panic. Of course, the minute you hear there’s some cancer cells, the panic kicks in, and you want it out and you want the maximum amount of treatment. But actually, in medicine, a lot of decisions can be made slowly. There are watchful waiting programs.

I want to suggest to people that, before you go for the screening, know these uncertainties exist, so that you can decide before the test comes back positive what you think you’d likely want to do, and then you can take time to think about it afterwards, and you can ask for a watchful waiting program.

I think one of the solutions would be to call these abnormal cells that we find on screening something other than “cancer.” The moment you hear that word, people’s immediate reaction is to get it out, because otherwise they think they will die of it. Watchful waiting is just something people find hard to do.

Hear Suzanne O’Sullivan speak at WIRED Health on March 18 at Kings Place, London. Get tickets at health.wired.com.