Experts are warning that many people diagnosed with ADHD may in fact have other, more easily treatable medical conditions producing similar symptoms, such as restlessness, poor concentration and memory problems. This matters because ADHD diagnoses are rising sharply, with an estimated 2.5 million people affected in England, while NHS assessment waiting lists stretch up to seven years, pushing many towards private clinics where checks may be less thorough and can happen online.

Professor Dinesh Bhugra, former president of the Royal College of Psychiatrists, said clinicians should look beyond a simple symptom checklist and ensure other causes are properly ruled out before diagnosis. A 2023 review by Canadian psychiatrist Joseph Sadek identified conditions including thyroid problems, iron deficiency and diabetes that can be mistaken for ADHD, and recommended a thorough medical evaluation for anyone being assessed. Doctors also note that genuine ADHD symptoms typically trace back to childhood, so a sudden onset in adulthood should prompt investigation of alternative causes, particularly since adult diagnoses have doubled over the past two decades.