The effects of low doses of diazepam on human performance in group administered tasks

1. The effects of diazepam in 5 mg dosage were assessed on a range of psychological tasks. Seventy‐eight healthy subjects were tested in an independent groups design; subjects were randomly assigned to either control, placebo or drug group. Treatments were administered orally under double blind conditions. 2. Auditory vigilance performance was unimpaired, in terms of (a) correct detections, (b) false alarms or (c) the subjects' estimates of the duration of the task. 3. The short term retention of digit strings was impaired by diazepam (P less than 0.05), especially for those digits presented in the middle of the sequence. 4. Searching for a few letters among many was significantly impaired by diazepam (P less than 0.01). 5. Diaepam had no effect on performance at a mental arithmetic task; neither was there a placebo effect. 6. Results were discussed in the light of the characteristics of drug sensitive tasks. It was concluded that characteristics such as feedback of results, monotony, and memory load are more likely to be drug sensitive when in combination than in isolation.