Abstract
Increasing numbers of preschoolers with disruptive behavior are referred to mental health professionals for evaluations of hyperactivity, prompting concerns that young children with "difficult temperament" are being misdiagnosed with attention-deficit/hyperactivity disorder (ADHD). This article provides a context for understanding the difficulties associated with diagnosing ADHD in preschoolers, reviews contemporary concepts of temperament, and examines recent efforts to integrate research on temperament and ADHD, with particular focus on the problematic construct of difficult temperament. We conclude preschoolers whose disruptive behaviors cause concern require a multidimensional approach to evaluation and planning for appropriate preventive intervention, and that assigning a label of difficult temperament provides neither reassurance nor license to engage simply in watchful waiting.