[Demonstration of bencyclane effects in a clinico-pharmacologic vigilance model]

The effects of 8 weeks' treatment with 2x 200 mg Bencyclan daily were investigated versus placebo in 50 patients. A clinical diagnosis had revealed the onset of organic mental disorders in all patients who, after fulfilling neurophysiologically and neuropsychologically defined screening criteria, were admitted to the trial. The patients were randomly allocated to two parallel groups of 25 for this controlled, double-blind study. Patients had to show 50% subvigil phases in a 15 min resting-EEG recording. We define such behaviour as a neurophysiological disturbance of vigilance. Scores in the Benton test were to be 2 points below the expected value or the NAF-score was to be above a standard value attained in an old people's home (greater than 14). On a neurophysiological level, inference statistical tests indicated effects in line with the hypothesis: A statistically significant difference in favour of Bencyclan was apparent after 8 weeks' treatment when compared with placebo. The Vigilance Index (VI) was higher under Bencyclan than after placebo. We regard the VI as a plausible indicator of vigilance-dependent disturbances in the elderly. On a behavioral level, Bencyclan was tendentially superior with respect to age-dependent complaints and performance-related activatedness, whereby one could not exclude the possibility that there were chance findings. The clear proof of efficacy on the neurophysiological level and the unclear effectiveness on the behavioral level can be attributed to the fact that time- and placebo effects were less marked on the former level. The intensive supervision of the patients led to considerable placebo effects on the behavioral level. Two groups of 25 patients are therefore not sufficient to be able to detect drug effects within a treatment period of only 8 weeks.