The efficacy of bromazepam and prazepam for the different components of anxiety: inhibition, asthenia and somatisation is evaluated in a multi-centric, comparative and randomised study, conducted as double blind and in parallel groups in 159 adult patients showing a manifest anxiety according to the F.D.A. criteria. After a 7 day wash-out period, the patients receive either bromazepam in a 12 mg/d dose or prazepam in a 40 mg/d dose, over 4 weeks (D0-D28), then in a decreasing dose from D28 to D43; follow-up is carried out using the anxious inhibition scale W.P.2, auto-questionnaire A.D.A., the Hamilton anxiety scale and the Tyrer questionnaire (benzodiazepine withdrawal symptoms questionnaire). Patients are evaluated seven times during the study: at day 7 for inclusion, day 0 for randomisation, then day 7 and day 14 for following visits, at day 28 for efficacy and tolerance evaluation, and at day 50 for utilisation and withdrawal evaluation. The major efficacy criteria are the evolution of inhibition, asthenia and somatisation as compounds of anxiety respectively evaluated by W.P.2 scale, asthenic partial score of autoquestionnaire A.D.A. and somatic partial score of Hamilton anxiety scale. The analysis of results don't show any significant difference between the two groups on the evolution of the components asthenia and inhibition. However the evolution of the somatic component clearly makes a significant difference in favour of bromazepam. There is also a significant difference in terms of global anxiolytic action efficacy, in favour of bromazepam.(ABSTRACT TRUNCATED AT 250 WORDS)