First of all, ADHD is hardly the only disease or disorder with an unclear cause. Alzheimer's, autism, and fibromyalgia come to mind. Second of all, here is a c

First of all, ADHD is hardly the only disease or disorder with an unclear cause. Alzheimer's, autism, and fibromyalgia come to mind. Second of all, here is a comprehensive list of peer-reviewed studies defending the existence of ADHD and the efficacy of amphetamines for ADHD (much better than some random anecdote of an improperly diagnosed taxi passenger): https://www.reddit.com/r/ADHD/comments/3at2u2/psa_the_existence_of_adhd_has_been_shown_by https://www.reddit.com/r/ADHD/comments/3at2u2/psa_the_existe... Admittedly, psychologists seem to have a problem properly diagnosing it, but let's not diminish a disorder suffered by millions every day.