title: Cognitive functioning during methadone and buprenorphine treatment: results of a randomized clinical trial.
abstract: Cognitive impairment in drug-dependent patients receiving methadone (MMP) maintenance treatment has been reported previously. We assessed cognitive functioning after at least 14 days of stable substitution treatment with buprenorphine (BUP) or MMP and after 8 to 10 weeks. We performed a randomized, nonblinded clinical trial in 59 drug-dependent patients receiving either BUP or MMP maintenance treatment and healthy normal controls (n = 24) matched for sex, age, and educational level. Thirteen patients dropped out of the study before the second testing was performed (BUP, n = 22; MMP, n = 24). A neuropsychological test battery was used to measure selective attention, verbal memory, motor/cognitive speed, and cognitive flexibility. In addition, subjective perceived stress was assessed with a questionnaire. Patients in both treatment groups performed equally well in all of the cognitive domains tested. Both BUP and MMP patients showed significantly improved concentration and executive functions after 8 to 10 weeks of stable substitution treatment. The control group achieved better results than the BUP and MMP groups in most cognitive domains, indicating cognitive impairment in the patients. Perceived stress did not show any significant change after 8 to 10 weeks of treatment, and no major differences were detected between the 3 groups. No effects of perceived stress on cognitive function were found. Our results indicate a cognitive impairment in patients receiving maintenance treatment with BUP or MMP compared with healthy controls. Selective attention improved in both patient groups during treatment. We propose that the improvement of attention may facilitate rehabilitation of drug-dependent patients.
authors.affiliation: Psychiatric Hospital, University of Munich, Munich, Germany. michael.soyka@privatklinik-meiringen.ch
authors.forename: Michael
authors.initials: M
authors.lastname: Soyka
authors.forename: Martin
authors.initials: M
authors.lastname: Lieb
authors.forename: Sabine
authors.initials: S
authors.lastname: Kagerer
authors.forename: Christina
authors.initials: C
authors.lastname: Zingg
authors.forename: Gabriele
authors.initials: G
authors.lastname: Koller
authors.forename: Peter
authors.initials: P
authors.lastname: Lehnert
authors.forename: Claudia
authors.initials: C
authors.lastname: Limmer
authors.forename: Heinrich
authors.initials: H
authors.lastname: Kuefner
authors.forename: Kristina
authors.initials: K
authors.lastname: Hennig-Fast
mesh_terms: D000701:Analgesics, Opioid / Q000627:therapeutic use*; D001288:Attention / Q000187:drug effects; D002047:Buprenorphine / Q000627:therapeutic use*; D003071:Cognition / Q000187:drug effects*; D006801:Humans; D008568:Memory / Q000187:drug effects; D008691:Methadone / Q000627:therapeutic use*; D009483:Neuropsychological Tests; D009293:Opioid-Related Disorders / Q000523:psychology / Q000534:rehabilitation*; D010352:Patient Dropouts; D010465:Perception / Q000187:drug effects; D011597:Psychomotor Performance / Q000187:drug effects; D013315:Stress, Psychological / Q000209:etiology; D013375:Substance Withdrawal Syndrome / Q000517:prevention & control* / Q000523:psychology; D011795:Surveys and Questionnaires; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000701:Analgesics, Opioid; D002047:Buprenorphine; D008691:Methadone