Large simple trials in psychiatry: providing reliable answers to important clinical questions.

The need for reliable evidence for medical interventions has long been recognised and the history of attempts to produce this evidence is thoroughly documented in the James Lind library (http://www.jameslindlibrary .org/). The status of randomised controlled trials as the most reliable method for evaluating the effects of treatments is now well established. Although the basic principles of the randomised trial have a long developmental history, it is often considered that the first modern medical randomised controlled trial came was the UK Medical Research Council trial of streptomycin in the treatment of tuberculosis (Medical Research Council, 1948). In the years following this trial, many randomised trials were conducted on a number of key questions in a number of disease areas including psychiatry and mental health. Many of these were funded by national public bodies, particularly National