Biederman and colleagues reported that a CBCL profile identified youngsters who were diagnosed with bipolar disorder. Some studies found that this CBCL profile does not reliably identify children who present with bipolar disorder, but nonetheless this CBCL does identify youngsters with severe dysfunction. However, the nature of the impairment of youngsters who fit this profile is unclear. The goal of this study was to describe the clinical characteristics of youngsters who fit this CBCL profile. The sample included 310 youngsters referred to an outpatient psychopharmacology clinic. There were 55 youngsters who fit the CBCL profile. These youngsters were compared to 255 youngsters who did not fit the CBCL profile. Measures included the CBCL, standardized measures of aggression and ADHD symptoms, youngsters' self-reported depression, DSM-IV diagnoses, and child and adolescent psychiatrists' ratings of impairment and functioning. Compared to youngsters who did not fit the CBCL bipolar disorder profile, youngsters who fit the profile had significantly higher scores on all but one CBCL scale and significantly higher levels of aggression. Youngsters who fit the CBCL profile also had greater psychosocial impairment and more DSM-IV diagnoses than youngsters who did not fit the profile. Youngsters who fit the CBCL profile exhibit severe dysregulation across multiple domains of functioning including attention, affective, and behavioral dysregulation that are not easily nor efficiently captured by extant DSM-IV diagnoses. These youngsters are not uncommon and comprise slightly less than 1 in 5 referrals to a child psychiatry clinic.