Treated 60 10-63 yr old anxious-neurotic inpatients complaining of insomnia with 10 or 20 mg of N-desmethyldiazepam, 200 mg of amylobarbitone sodium, or placebo, given at night. The hypnotic effects of these treatments were assessed by self-rating, psychiatrists' ratings, and night nurses' observations after 1 night's treatment and after a week of treatment, and compared with pretreatment values. The residual effects of the treatments were estimated 12 hrs after ingestion using a series of cognitive and motor tasks. No significant differences between the treatments were found after 1 night. After the week of treatment, the benzodiazepine groups were achieving the best quality of self-rated sleep with fewest subjective feelings of hang-over. Some improvement in performance was found over time for all groups. However, on 2 motor tests, the higher dose of N-desmethyldiazepam was associated with less improvement (i.e., some impairment relative to placebo was detected). (15 ref) (PsycLIT Database Copyright 1975 American Psychological Assn, all rights reserved)