There has been a sharp increase in the number of adults who think they have attention deficit hyperactivity disorder (ADHD). The NHS has been overwhelmed by the number of patients looking for a diagnosis. Now thousands of people are turning to private clinics for assessment instead.Panorama reporter Rory Carson poses as a patient to reveal some clinics charging large fees for a short online consultation, as well as evidence suggesting that diagnoses are being handed out to almost everyone who books an appointment.The programme also reveals clinics prescribing powerful drugs without carrying out proper checks.