A comparison of cognitive impairment due to benzodiazepines and to narcotics.

In an attempt to determine the source of cognitive impairment in 106 consecutively admitted patients at the Johns Hopkins Chronic Pain Treatment Center, EEG, the Wechsler Adult Intelligence Scale, Memory Quotient, and Bender Gestalt tests were administered. Patients receiving benzodiazepines alone demonstrated alterations in cognitive functioning and EEG evidence of a sedative effect. Patients receiving narcotics alone and a group of patients not receiving medication did not show signs of cognitive impairment. The effects of benzodiazepines on sleep and perception of chronic pain, in combination with the cortical changes that they produce, imply that these drugs should not be used in most patients with chronic pain.