HIGH FALSE ALARM RATES ON A VIGILANCE TASK MAY INDICATE RECREATIONAL DRUG-USE

Neuropsychologists need more sensitive methods to detect and measure r ecreational drug use in both research and clinical settings. In a stud y comparing the sensitivity of information processing tasks and neurop sychological instruments to detect early HIV-related cognitive decreme nts, 18 of 129 subjects tested positive for recreational drugs. Sixtee n of these 18 subjects had elevated false alarm rates on one of the in formation processing tasks, the vigilance task. Another 45 subjects wh o tested negative for recreational drugs also had elevated false alarm rates. Neuropsychological measures of premorbid functioning, attentio n, speed of information processing, and manual dexterity were lower in the high false alarm subjects than in the remaining 66 drug-negative, low false alarm subjects. These results suggest that a high false ala rm rate may reflect long-standing cognitive disturbances and the effec ts of drug use. The vigilance task may be a sensitive and efficient sc reening tool for recreational drug use.