Cognitive functioning during methadone and buprenorphine treatment: results of a randomized clinical trial.

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.

Personality disorder and chronicity of addiction as independent outcome predictors in alcoholism treatment.

OBJECTIVE: A prospective four-year study examined which components of addiction severity predicted time to relapse among 112 adults with chronic alcoholism who participated in a comprehensive outpatient treatment program. METHODS: Recruited from emergency, inpatient, and outpatient facilities, patients were admitted into the program consecutively between March 1998 and June 2002. Alcohol abstinence was carefully monitored for four years from admission by regular contacts and urine and blood analyses. Alcoholism characteristics and personality disorders were assessed with structured interviews and the International Diagnostic Checklists for Personality Disorders. RESULTS: Among a variety of potential variables, only presence of a personality disorder and chronicity of addiction were independently associated with a decrease of cumulative four-year abstinence probability. CONCLUSIONS: Their high predictive values suggest that chronicity and personality disorder rank among the most important characteristics of addiction severity.

Retention rate and substance use in methadone and buprenorphine maintenance therapy and predictors of outcome: results from a randomized study.

This was a 6-month, randomized, flexible-dose study comparing the effects of methadone (Meth) and buprenorphine (Bup) on retention rate and substance use in a sample of 140 opioid-dependent, primarily heroin-addicted, patients who had been without opioid substitution therapy in the 4 weeks prior to the study. The major aims were to compare the efficacy of Bup and Meth in a flexible dosing regimen and to identify possible predictors of outcome. There were no major inhomogeneities between treatment groups. All patients also received standardized psychosocial interventions. Mean daily dosages after the induction phase were 44-50 mg for Meth and 9-12 mg for Bup. Results from this study indicate a favourable outcome, with an overall retention rate of 52.1% and no significant differences between treatment groups (55.3% vs. 48.4%). Substance use decreased significantly over time in both groups and was non-significantly lower in the Bup group. Predictors of outcome were length of continuous opioid use and age at onset of opioid use, although these were only significant in the Bup group. Mean dosage and other parameters were not significant predictors of outcome. Overall, the results of this study give further evidence that substitution treatment is a safe and effective treatment for drug dependence. Meth and Bup are equally effective. Duration of continuous opioid use and age at onset were found to have predictive value for negative outcome. The intensity of withdrawal symptoms showed the strongest correlation with drop-out. Future studies are warranted to further address patient profiles and outcome under different substitution regimens.

Less impairment on one portion of a driving-relevant psychomotor battery in buprenorphine-maintained than in methadone-maintained patients: results of a randomized clinical trial.

BACKGROUND: Cognitive impairment in drug-dependent patients under methadone maintenance treatment has been reported before. We assessed whether patients under buprenorphine, a partial mu-opioid agonist, perform better in cognitive tests measuring psychomotor performance as described in previous nonrandomized studies. METHODS: We performed a randomized clinical trial in 62 drug-dependent patients under either buprenorphine or methadone treatment. Sixteen patients dropped out of maintenance therapy, before the testing was performed, after 8 to 10 weeks of treatment. Several subtests of the Act & React Test System test battery were used measuring visual perception, selective attention, vigilance, reactivity, and stress tolerance. FINDINGS: Although there were no differences in cognitive function at baseline, patients under buprenorphine treatment showed partially better results in some of the domains tested. The used tests are relevant when assessing driving ability. There was a significant correlation between dose of buprenorphine and some test results. We also found a correlation between age and reaction time and between duration of opioid dependence and results in some subtests. INTERPRETATIONS (CONCLUSIONS): When comparing both treatments in drug dependent patients, buprenorphine produces partially less impairment on cognitive functions in some of the subtests of the psychomotor battery than methadone. This difference is specially relevant when it comes to driving ability and social functioning.