Mental illness is associated with high burden of disease and it has severe individual and societal consequences. It will be of immense value to be able to intervene in risk groups identified before onset of psychosis and other severe psychiatric disorders. In first episode psychosis, early Intervention services with team-based intensive case management and family involvement are superior to standard treatment in reducing psychotic and negative symptoms and comorbid substance abuse and improving social functioning and user satisfaction. As an introduction, the results of the OPUS-trial will be presented together with meta-analyses based on similar trials. The basic principles for working in an early intervention team will be presented and discussed. Involving families is a cornerstone in early intervention. Family involvement can be in many different formats, depending on the needs and preferences of the patients and the relatives. The multifamily group approach will be presented with vignettes and tried out in role plays. The implementation of OPUS all over Denmark will be presented together with the Danish OPUS-fidelity study.