Psychological performance in anxious patients treated with diazepam.

1. After each week of a flexible dosage treatment with either diazepam, amylobarbitone or placebo anxious patients were assessed by a comprehensive battery of psychiatrist's ratings, subjective tests and psychological performance tasks to detect the clinical and psychological effects of the drugs. 2. Self rated anxiety and insomnia were improved significantly by diazepam, while amylobarbitone improved only the self rated insomnia. 3. An impairment of performance relative to placebo was detected on two performance tasks after the barbiturate and on six performance tasks after the benzodiazepine. 4. The patient's reported level of anxiety under each treatment condition was related to the performance on the five tasks showing drug effects, thus confirming the postulated inverted U-shape relationship between drive and performance.