ADHD Diagnosis - Getting the Right One From the NHS In order for people to receive an accurate diagnosis of ADHD the NHS requires a thorough assessment. The BBC investigation found that certain private clinics could be distributing incorrect diagnoses and medications. A valid ADHD diagnosis is based on symptoms, https://telegra.ph/Whats-The-Reason-Private-ADHD-Assessment-Edinburgh-Is-Everywhere-This-Year-03-06