Diminished brain functional magnetic resonance imaging activation in patients on opiate maintenance despite normal spatial working memory task performance.

Objectives: Despite the beneficial impact on the reduction of addictive behavior, opiate maintenance therapy has been associated with negative effects on cognitive and psychomotor functioning. This may limit the outcome of behavioral strategies, rehabilitation, and reintegration into society. The objective of the study at hand was to investigate the effect of buprenorphine and methadone maintenance therapy on visuospatial working memory performance.

Methods: Visuospatial working memory performance of 13 patients, receiving either methadone or buprenorphine, was investigated and compared to 13 control participants using functional magnetic resonance imaging.

Results: Altered neuronal activation was found in the patients, including brain areas associated with working memory performance and addiction. Behavioral performance on the visuospatial working memory task was similar across groups.

Conclusions: Results indicate that there are no robust impairments of visuospatial capabilities in patients on opiate maintenance, but altered neuronal activation in working memory-related brain areas-due to chronic presence of opiates-may limit cognitive performance on complex cognitive tasks. Factors in therapeutic strategies that may support rehabilitation of patients' cognitive performance are discussed.