Family dysfunction ruins lives. We all know this; many of us will have personally seen its corrosive effects. Even if we’ve been fortunate enough to avoid this personal knowledge, we can’t escape the effects staring up at us from the pages of our newspapers. Two of the problems that have received the most attention in recent years are child abuse and neglect, and conduct disorder (severe anti-social behaviour) in children. Although these problems are frightening in their severity and scale, the good news is that although we can’t solve them completely, we can do something about them. Early intervention programmes offer a chance of breaking, even preventing, their cycle, if the programmes are truly effective. Unfortunately, not all of them are.