Cognitive-motor performance of methadone-maintained patients

Fifty-four methadone-maintained patients and 54 healthy controls, matched f or age, gender and educational attainment, completed a battery of six cogni tive-psychomotor performance tests. Results of previous studies were replic ated in four areas. An attention task was performed less well by patients [ mean difference more than 0.7 standard deviations (SD)] as was a tachistosc opic perception task (0.3 SD). On a simple-choice reaction test, patients s howed higher speed in decision making and motor reaction as well as an incr eased number of decision errors (0.3 SD each). Performing a tracking test, patients showed less deviations (0.4 SD) combined with more time needed (0. 8 SD). Our data go beyond previous (seemingly inconsistent) research findin gs by showing that patients did less well by more than 0.6 SD when on highe r speed levels. Absolving a test on visual structuring, more patients than controls achieved a 100% accuracy level (52 vs. 30%), but at the same time patients were slower (0.6 SD) than controls. An inferior test performance o f patients in methadone maintenance treatment has been confirmed in some ar eas, especially in attention. However, the fairly moderate size of these ef fects and the fact that in the majority of measures the observed variance w as better explained by sociodemographic features than by group membership l ead on the conclusion that belonging to the group of methadone patients alo ne is not necessarily sufficient to predict an impairment in cognitive-psyc homotor skills. To conclude, assessment of fitness for certain tasks or occ upations should be done individually for each patient and should take into account comorbidity, including the extent of alcohol and other drug use. Co pyright (C) 2000 S. Karger AG, Basel.