A topic in Clinical Evidence summarizes the results of one systematic review (search date 1996) including 17 RCTs with a total of 2044 people and 1 subsequent RCT. The systematic review found that benzodiazepines significantly improved symptoms over 2–9 weeks (effect size 0.70, CI not reported) compared to placebo. The subsequent RCT (n=310, comparing 3 interventions) reported response in 73% of patients on diazepam compared to 56% of patients on placebo, p<0.01). RCTs and observational studies found that benzodiazepines increased the risk of dependence, sedation, industrial accidents, and road traffic accidents. Clinical evidence category: Trade off between benefit and harm.