Correlations among measures of response to benzodiazepines in man.

A retrospective analysis of five studies using benzodiazepines and one using a benzodiazepine-like drug, zopiclone, and involving 61 subjects in toto was carried out. All used a placebo control and all acute studies incorporated pre-treatment values as well. Eight variables which have previously been shown to be sensitive to benzodiazepine action and which covered a range of physiological, psychological and subjective measures were chosen. Within-subject correlations between drug minus placebo values for these variables were computed to examine relationships between the measures while the subjects were taking benzodiazepines. It was found that closely related measures within system were significantly correlated but other correlations were sparse. However under limited conditions, i.e., several doses of one drug in the same subjects as in the zopiclone study, a consistent pattern of effects was shown across measures, resulting in half of the possible correlations showing statistical significance. A similar pattern was shown in patients after 2-4 weeks treatment with benzodiazepines.