Background: The Child Bipolar Questionnaire (CBQ) is a rapid screener with a Core Index subscale of symptom dimensions frequently reported in childhood-onset bipolar disorder (BD) and scoring algorithms for DSM-IV BD, with and without attention-deficit/hyperactivity disorder (ADHD), and the proposed Narrow, Broad, and Core phenotypes. This report provides preliminary data on the reliability and validity of the CBQ.
Method: Test-retest and inter-rater reliability of the CBQ were assessed. The ability of CBQ screening diagnoses and of the CBQ Core Index subscale to effectively predict diagnostic classification by structured interview was assessed using the K-SADS P/L.
Results: Preliminary test-retest data showed excellent reliability for both the CBQ total score (r = 0.82) and the Core Index subscale (r = 0.86). Preliminary validity data was also promising. CBQ screening algorithms performed with a specificity of 97% and a sensitivity of 76% in classifying subjects with K-SADS P/L diagnosis of BD vs. no BD. The Core Index subscale had excellent agreement with K-SADS P/L diagnosis (k = 0.84) in classifying BD, ADHD-only, and no diagnosis and demonstrated 100% sensitivity and 86% specificity in classifying BD vs. no BD.
Limitations: This preliminary data is from a sample enriched with bipolar disorder cases. Further validation is needed with samples in which childhood-onset BD is rarer and diagnoses more diverse.
Conclusions: The CBQ shows potential for rapid and economically feasible identification of possible childhood-onset BD cases as defined by DSM-IV criteria as well as by alternate disease phenotypes. Further validation studies will focus on inpatient and outpatient samples with a broader range of variability.