ABSTRACT
Symptoms of common mental disorders in children and adolescents have been conceptually organized into two broad dimensions. One dimension, which is the focus of this chapter, has been labeled as undercontrolled or externalizing and includes various acting out, disruptive, delinquent, hyperactive, and aggressive behaviors. e second dimension has been labeled as overcontrolled or internalizing and includes such behaviors as social withdrawal, anxiety, and depression (see Ollendick & Sander, this volume). e distinction between internalizing and externalizing problems is well supported by a number of factor analytic studies (Achenbach, 1995; Lahey et al., 2008).
