Several famous people have spoken about the rise in ADHD diagnoses. Actor Tom Cruise said that the medicines usually given to people with ADHD were like illegal drugs. Others disagreed with him because the amount of medicine given to people with ADHD does not cause addiction. There have been many studies about the effectiveness of the medicines used with ADHD. One certain study found that the medicine did help over a long time, but did not help more than other types of treatment.