Abstract: Mental illnesses such as schizophrenia, depression, dementia and problems such as learning disability and substance misuse are common. They are often life-long and frequently lead to profound degeneration in the functioning and quality of life of the sufferers and their carers. Much good evidence about the treatment of these conditions already exists but has never been collated in one accessible form designed for those with a specific interest in mental health issues. Objectives The EU-( project aims to improve dissemination of trial-derived evidence on effectiveness of mental health treatment by: * enhancing accessibility of specialised CRG registers by making the five mental health registers available on-line * enhancing indexing of mental health trials in The Cochrane Library CENTRAL * converting the report-based registers into study-based registers * producing a free-for-all website offering on-line access to the indexed pooled register of mental health trials-a unique CD-ROM, The EU-( Mental Health Library, updated twice a year, published by Update Software Ltd and containing Cochrane systematic reviews relating to mental health issues, The Database of Reviews of Effectiveness relating to mental health issues, an indexed and coded register of controlled clinical mental health trials, and evidence-based national or local treatment guidelines relevant to mental health Ultimately, the EU-( project aims at promoting evidence-based psychiatry by offering easy access to trial data, by offering improved structures for Cochrane reviewers, and by improving mental health content of the Cochrane Library as well as offering a new mental-health-specific electronic product, the EU-PSI Mental Health Library. The EU-( project is a concerted action funded by the European Commission. Project will start September 1, 2000.