A Preliminary Meta-Analysis of the Child Behavior Checklist in Pediatric Bipolar Disorder Eric Mick, Joseph Biederman, Gahan Pandina, and Stephen V. Faraone Background: A possible explanation for the ongoing controversy surrounding pediatric bipolar disorder is that differences in assessment methodologies lead to conflict- ing results. One way to address methodological differ- ences in assessment across studies is to use a single standardized assessment of psychopathology to calibrate the findings reported in different studies. To this end, we conducted a meta-analysis of several studies that have employed the Child Behavior Checklist in the assessment of children with a diagnosis of bipolar disorder. Methods: MEDLINE was searched for all publications that utilized the Child Behavior Checklist in addition to structured diagnostic interviews to assess pediatric bipo- lar disorder. Random effects models were used to calcu- late combined estimates of Child Behavior Checklist clinical subscales. Results: Children with bipolar disorder had scaled scores of 70 in the Aggression, Attention Problems, and Anx- ious/Depressed subscales of the Child Behavior Checklist. The Child Behavior Checklist was useful in distinguishing bipolar from attention-deficit/hyperactivity disorder subjects. Conclusions: While there was a significant heterogeneity in estimates between studies, a consistent pattern of elevations in inattention/hyperactivity, depression/anxiety, and aggression was identified. Biol Psychiatry 2003;53: 1021–1027 © 2003 Society of Biological Psychiatry Key Words: Bipolar disorder, disruptive behavior disor- ders, assessment, children Introduction T here is a growing consensus that many seriously disturbed children are afflicted with severe affective dysregulation and high levels of agitation, aggression, and dyscontrol that pose severe diagnostic and therapeutic challenges to the practicing community. Although the true diagnosis of these children remains uncertain, our work shows that they meet criteria for bipolar disorder (Bieder- man et al 1998; Faraone et al 1997; Wozniak et al 1995). Currently, a major impediment to the study and treatment of children with bipolar disorder is disagreement over the assessment and definition of the disorder. Existing research suggests that children with chronic and continuous severe irritability, affective storms, or prolonged and aggressive temper outbursts are increas- ingly being diagnosed as bipolar disorder (Carlson et al 2000; Weckerly 2002; Wozniak et al 1995). Systematic studies of children and adolescents also show that rates of attention-deficit/hyperactivity disorder (ADHD) range from 60% to 90% in pediatric patients with bipolar disorder (Borchardt and Bernstein 1995; Geller et al 1995; West et al 1995; Wozniak et al 1995). It is largely due to this atypical presentation of bipolar disorder in children that much of the confusion, disagreement, and debate among clinicians and researchers has developed (Klein et al 1998). One possible reason for the ongoing controversy about pediatric bipolar disorder is that heterogeneity in the presentation of the disorder has led to different assessment methodologies that could lead to different conclusions and descriptions of children with bipolar like symptoms that are independent of the underlying psychopathology being assessed. This is not a trivial academic debate, since confusion over the definition and categorization of pedi- atric bipolar disorder inhibits efforts at developing the scientific and therapeutic foundation of the disorder, leaving afflicted patients and families with few options. One method of addressing this issue is to synthesize data from the extant literature using a common metric against which to compare patients ascertained in different studies. An instrument that could serve as such a metric is the Child Behavior Checklist (CBCL). The CBCL is one of the best-studied, empirically derived, checklists avail- able that measure psychopathology (Achenbach and Edel- brock 1983; Achenbach 1991; Achenbach et al 1991). It has excellent psychometric properties, and a large body of research demonstrates its reliability and validity in both clinical and nonclinical populations (Achenbach 1991). From the Pediatric Psychopharmacology Unit, Child Psychiatry Service, Massa- chusetts General Hospital (EM, JB, SVF); Harvard Medical School (EM, JB, SVF), Boston, Massachusetts; and CNS Clinical Development Division (GP), Janssen Pharmaceutica Products, L.P., Titusville, New Jersey. Address reprint requests to Eric Mick, Sc.D., Massachusetts General Hospital, Pediatric Psychopharmacology Research, 15 Parkman Street, WACC 725, Boston MA 02114. Received July 10, 2002; revised January 3, 2003; accepted February 4, 2003. © 2003 Society of Biological Psychiatry 0006-3223/03/$30.00 doi:10.1016/S0006-3223(03)00234-8