Why Do Some People Believe They Have a Mental Illness Without a Diagnosis?

Mental health issues like depression and anxiety are on the rise, especially among young people. With this increase, there’s also a growing demand for treatment, leading to more prescriptions for psychiatric medications. This surge ties in with a stronger public awareness about mental health; messages about it are everywhere—from news outlets to social media. Governments and organizations are stepping up with initiatives to raise awareness, prevent issues, and provide effective treatment.

This cultural emphasis on mental health brings many positives, such as reducing stigma and encouraging people to seek help. But there are concerns, too. Some argue that social media may be contributing to mental health issues and that common feelings of unhappiness are being overly medicalized through frequent use of diagnostic language and “therapy talk.” British psychologist Lucy Foulkes introduces an intriguing idea known as the “prevalence inflation hypothesis.” She suggests that heightened awareness about mental illness could lead people to misdiagnose themselves when facing mild or temporary struggles. This idea reflects a broader trend we call “concept creep” in how we define mental illness. Our research supports this, showing that definitions of mental illness have broadened over time, and people now interpret mental health conditions in varying ways.

In our study, we looked at self-diagnosis, defined as when someone believes they have a mental health condition without professional confirmation. We considered someone to have a “broad concept of mental illness” if they included a wide array of experiences—sometimes even mild ones—as part of what they see as a disorder. We surveyed a representative group of 474 American adults, asking if they believed they had a mental disorder and if they had a professional diagnosis. Our findings showed that mental illness was common in our sample: 42% reported self-diagnosed conditions, most of whom had also received confirmation from a professional. Unsurprisingly, a major predictor for reporting a diagnosis was experiencing considerable distress.

The next biggest factor was having a broad definition of mental illness. When we accounted for distress levels, people with a more expansive view of mental health conditions were much more likely to report having a current diagnosis. The data reveals a trend: individuals with the broadest definitions (the top quarter of our sample) reported mental illnesses more frequently, especially when they were dealing with high distress levels. Interestingly, those with higher mental health awareness and lower stigma were also more likely to report a diagnosis.

Our research highlighted two other notable trends. First, people who self-diagnosed without professional confirmation generally had broader concepts of mental illness than those who received a professional diagnosis. Second, younger and more politically progressive participants were more likely to report a diagnosis, a trend that aligns with other studies, and they also held broader definitions of mental health disorders. This trend partly explains their higher rates of self-diagnosis. Our results suggest that these broader definitions encourage people to label their experiences as mental health issues, which might inflate the perceived prevalence of mental disorders. Those more inclined to view their distress as a disorder tend to identify as having a mental illness.

While our findings don’t definitively show whether those with broader definitions are over-diagnosing or if those with narrower definitions are under-diagnosing, they do raise some important points. For instance, they suggest that while raising mental health awareness is vital, it could also lead to the mislabeling of common issues as disorders. Misdiagnosis can be problematic, as a diagnostic label can become a central part of someone’s identity, framing challenges as fixed traits. Additionally, unnecessary self-diagnosis may lead people with mild distress to seek help that’s not actually suitable for them. A recent Australian study found that individuals with mild distress who sought therapy often ended up feeling worse.

These effects are particularly concerning for young people, who not only experience mental health struggles at higher and growing rates but are also more likely to hold broad views of mental illness, often influenced by social media. It’s uncertain if this widening of definitions is fueling the youth mental health crisis. As society shifts towards more inclusive definitions of mental illness, we may see both positive and negative outcomes. While it can help reduce stigma and normalize mental health conversations, it also risks pathologizing ordinary distress. This is a delicate balance we must handle carefully as we continue promoting mental health awareness.