Neuropsychological functioning of opiate-dependent patients: a nonrandomized comparison of patients preferring either buprenorphine or methadone maintenance treatment.

OBJECTIVES

In the present study, we investigated whether buprenorphine as a partial mu-opioid receptor agonist is associated with less cognitive impairment than methadone.

METHODS

Neuropsychological functioning of opioid-dependent patients, previously assigned to methadone (MMP, n = 30) or buprenorphine (BMP, n = 26) maintenance treatment according to their own preference, was compared and dose effects were investigated.

RESULTS

MMP and BMP performed equally well on all measures of neuropsychological functioning including the trail making test, the continuous performance test, and a vigilance task. However, patients receiving a higher dose of methadone were impaired in a vigilance task.

CONCLUSIONS

In a free-choice administration of methadone or buprenorphine, there seems to be no difference in cognitive functioning. Possible explanations are discussed.