The practice of child and adolescent psychiatry is more complex now. More is known about the neurobiology of common psychiatric disorders. Sophisticated diagnostic systems can be downloaded for nonprofit use from the Internet (e.g., Kaufman et al., 1997). Treatment alternatives for a single disorder have proliferated (e.g., Clarke et al., 1999; Emslie et al., 1997). Self-help pediatric mental health consumer groups are now common, often with Web sites such as http://www.chadd.org. Often multiple choices exist, some of them vastly disparate, with each choice professing at least some efficacy. A wilderness camp experience and an atypical antipsychotic may each show at least some usefulness for the same disorder. With more choices and more information, decision-making is more complex. These changes in conceptualizing, treating, and informing about adolescent psychiatric disorders affect the alliance between physician and parents. Sharing evidence-based thinking (EBT) with parents and adolescent--thinking that integrates the best research evidence with clinical expertise and patient preferences (Sackett et al., 2000)--is useful when parents, an adolescent, and the treating physician are considering treatment decisions or diagnostic dilemmas. This article describes four ways EBT strengthens the alliance with parents.