ABSTRACT
It is becoming increasingly clear that a significant number of children and adolescents have severe and impairing emotional or behavioral problems. Prevalence estimates of childhood psychopathology vary greatly depending on the age group studied, the type of disorders included, and the method of assessment used. However, epidemiological studies conducted in the United States, New Zealand, Canada, Puerto Rico, and the Netherlands indicate that from 9% to 22% of children and from 18% to 22% of adolescents have signs of significant problems in adjustment (Frick & Silverthorn, 2001). Furthermore, research has indicated that the form that these problems take can largely be conceptualized along two major dimensions. One dimension, which is the focus of the current chapter, has been labeled as undercontrolled or externalizing and includes various acting out, disruptive, delinquent, hyperactive, and aggressive behaviors. The second broad dimension of childhood psychopathology has been labeled as overcontrolled or internalizing and includes such behaviors as social withdrawal, anxiety, and depression. This basic distinction between internalizing and externalizing problems has been well supported by a number of factor analytic studies. There is even debate as to whether or not more fine grained distinctions within these broad categories provide any additional useful information for understanding children with psychopathological conditions (Achenbach, 1995; Achenbach & Edelbrock, 1978; Quay, 1986).
