Specialist ADHD services for adults are stopping taking on new patients as they struggle to cope with demand, a BBC investigation has shown.
The BBC has identified 15 local areas that have closed waiting lists and another 31 that have introduced tighter criteria, making it more difficult to access support.
Reacting to our investigation, Prof Anita Thapar, chair of NHS England's ADHD taskforce, said the findings were "disturbing", adding there were "enormous risks" for patients.
It comes as she prepares to publish her report into the state of ADHD services on Thursday, which is expected to recommend an overhaul of the way people are supported.
ADHD - attention deficit hyperactivity disorder - affects the way the brain works and can cause people to act impulsively and become easily distracted.
