This book describes an innovative approach to the evaluation of complex health interventions, assessing what interventions work, how and for whom. Rejecting the stalemate between trials and realist evaluation, it draws on the best of both. Randomised controlled trials and systematic reviews offer the least biased means of assessing intervention effects but tell us little scientifically about how interventions work. Policy-makers and practitioners are also not supported to decide which inte...

Young people’s mental health is in crisis, with many – especially those from disadvantaged backgrounds – struggling academically and with the later transition to employment. Feeling excluded, many young people turn to harmful behaviours, such as vaping and alcohol use, for escape and a sense of belonging.Schools are increasingly expected to address these issues but often lack the time and expertise to do so effectively. Based on the author’s research, including the successful ‘Lear...