Sustained attention in methadone patients.

Sustained attention was examined in chronic, high-dose (70-120 mg) methadone patients with a modified Continuous Performance Test (Rosvold et al., 1956) 45 min in duration. Working and nonworking patient groups, and drug-free ex-addict and opiate-naive comparison groups were tested at high, moderate, and low signal rates. Groups did not differ overall in accuracy, response latencies, or commission errors. The working patients, however, performed better at the high than at the lower signal rates, and had poorer accuracy and longer latencies at the low rate than the comparison groups. The nonworking patients had different results; they made more commission errors at the high signal rate than the other three groups.