Millions of people across the world are being told they have a mental health condition even though their symptoms are mild or likely to fade on their own, according to new research examining how diagnostic criteria have expanded in recent decades. The findings raise questions about whether some of the sharp global rise in conditions such as depression and attention deficit hyperactivity disorder reflects genuine illness or simply broader definitions of what counts as a mental disorder.
The paper, published in the ISPCE Bulletin by Prince Kouassi of the American University in Dubai, focuses on a phenomenon known as overdiagnosis. This occurs when someone is given an accurate label for symptoms that are transient or mild and unlikely to benefit from treatment, rather than being wrongly diagnosed altogether.
A key example cited is ADHD. Under the older DSM-IV manual, symptoms had to appear before the age of seven and cause noticeable impairment. When the DSM-5 was introduced, the age of onset was raised to 12 and the impairment requirement was dropped. Research referenced in the paper shows that ADHD prevalence in the US rose from around 7.4% to almost 11% largely as a result of these changes, rather than any genuine increase in the condition itself.
The paper also highlights depression research suggesting that a substantial proportion of people diagnosed recover without any formal treatment. Large-scale trials found that well over a third of patients given a placebo improved significantly, while roughly half of those receiving only standard care no longer met the criteria for major depression after treatment ended. This suggests many diagnosed cases may have resolved naturally regardless of intervention.
Kouassi argues that these expanding definitions carry real consequences. People given unnecessary labels can face stigma, changes in how they are viewed by employers or loved ones, and exposure to medication side effects they did not need. In the US alone, the cost of ADHD medication linked to overdiagnosis has been estimated at between 320 million and 500 million dollars.
The research also points to a wider paradox. In countries such as Australia, mental health spending rose by 178% between the early 1990s and 2011, alongside a huge increase in antidepressant prescriptions, yet overall rates of anxiety, mood and substance use disorders did not fall. This suggests that simply expanding treatment provision does not necessarily reduce the underlying prevalence of diagnosed conditions.
The paper stops short of blaming overdiagnosis entirely for rising global mental health figures, noting that gaps in treatment quality likely play a role too. It calls for clinicians to consider a staged approach, observing patients before issuing a formal diagnosis, and for governments to fund research into how widely used diagnostic checklists are applied in practice.
With mental health provision expanding rapidly in developing nations such as the United Arab Emirates, the author suggests these countries have an opportunity to build safeguards against overdiagnosis into their systems from the outset, rather than repeating patterns seen elsewhere.
