Clobazam and diazepam: The differential effects on psychomotor performance and subjective feelings in normal volunteers with high neuroticism level

Abstract

AbstractThe purpose of this study was to investigate the possible differences between diazepam and clobazam with regard to their effects on psychomotor performance and subjective feeling in normal volunteers with high neuroticism levels. The study was designed as a double‐blind, crossover, single‐dose comparison of clobazam, diazepam, and placebo. Using the Maudsley Personality Inventory (MPI), 12 healthy male volunteers exhibiting high neuroticism scores were selected. Clobazam 10 mg, diazepam 5 mg, and placebo were administered orally. Measurements of psychomotor performance and subjective ratings of mood states were performed before and 1.5 and 6 hr after administration. Prior to the experiment the subjects were trained with the performance tests to minimize interference of learning effects with drug effects. Between the three treatments there were 1‐wk intervals. Both clobazam and diazepam significantly lowered choice‐reaction task performance as compared to placebo. Only clobazam lowered mirror‐drawing task performance significantly differently from placebo. Significant changes in subjectively rated mood states were also seen after clobazam only. These mood changes appeared to indicate some disinhibitory or stimulant effects. The demonstrated differences between the effects of both anxiolytics are discussed in the context of experimental design characteristics and the subjects' high level of neuroticism. Some of the observed effects may be due to an interaction of drug effects with neurotic tendencies rather than to generalized drug effects per se.