Multivariate symptom analysis related to response to lorazepam treatment.

In an attempt to explain the marked inter-trial differences in the percentage of patients reported to benefit from the anxiolytic agent lorazepam, a statistical analysis was carried out on the scores from a psychiatric symptom questionnaire, completed before and after treatment with lorazepam, by 69 psychiatric out-patients. Most of the patients presented with a mixture of different syndromes, with moderate to severe symptoms, and had already failed to respond to other treatment. Forty of the patients showed a favourable response to lorazepam. Multivariate analysis of the strength of 6 symptom clusters versus therapeutic response in this diagnostically heterogeneous patient sample revealed that, in addition to anxiety, there was a high relationship also between phobic and psychosomatic symptom scores and response to lorazepam. The relationship between depression scores and response was only of borderline significance, and that for hysteria and obsessionality was poor. It is suggested that one explanation of inter-trial differences in the percentages of patients improved by lorazepam may be that they are due to differences in the diagnostic composition of the patient populations studied.