Abstract
Evidence-based practice (EBP) is the subject of vigorous controversy in the field of mental health. In this paper I discuss three distinct but interrelated controversies: how inclusive the mental health evidence base should be; whether mental health practice is a variety of applied science; and when and how the effectiveness goal in mental health is defined. I provide examples of evidence-based policy in mental health. These controversies pertain as well to general medicine. To the extent that they remain unresolved, evidence-based policy making may lead to ineffective and limited care.