Changes in EEG, blood levels, mood scales and performance scores during long term treatment with diazepam, phenobarbital or placebo in patients.

1. The patient population consisting of fifteen patients was divided into three groups, namely: diazepam group, phenobarbital group and placebo group. After three weeks the medicated groups were switched to placebo for a week and the placebo group was given phenobarbital. 2. The parameters to be assessed once a week comprised frequency-analyzed EEG recordings, performance in two attention tests and subjectively estimated mood modalities. 3. The EEG analysis suggested that EEG patterns: a) were drug-dependent, with a differential distribution for each drug of the four frequency bands analyzed; b) showed no change during the three-week treatment period; c) changed on cessation of medication or on switch from placebo to active medication; d) were task-dependent and changed in a systematic way with the level of activation (stress, vigilance or relaxation). 4. The results would allow a better understanding of the clinical course, the choice of therapeutic measures and of the underlying mechanisms of action.