A pilot study has examined 45 patients with chronic pain who filled in a questionnaire when attending a treatment clinic for chronic pain. Included in the questionnaire were questions pertaining to concentration, attention, distractibility, impulsivity, reading retention, coordination, temper, and short-term memory. If patients answered positively to having deficiencies in five or more of these specific areas, this was taken to indicate that the patient had ADD. The study found ADD in over 37% of chronic pain patients. The researchers suggest that the pain causes alterations in the nervous system that lead to ADD, by promoting a hyperactive state. The study sheds light on other conditions that may affect patients with chronic pain, giving physicians further insight into how to further help people who suffer with chronic pain.