Pediatric bipolar disorder (PBD) is a serious psychiatric disorder, and is associated with debilitating symptoms and functional impairment (American Psychiatric Association, 1994
). The symptom presentation of PBD is characterized by significant episodic mood lability, mixed mood states, high rates of comorbidity, and rapid cycling, which distinguish the early-onset pediatric phenotype from its adult-onset counterpart (Pavuluri, Birmaher & Naylor, 2005
). PBD is also characterized by a chronic and refractory course, low recovery, and high relapse rates (Geller, Craney, Bolhofner, DelBello, Axelson, Luby, et, al, 2003
), which places a significant strain on parents and providers alike. Even with the highest quality evidence-based approaches, response to treatment is notoriously poor. As promising interventions continue to be developed and tested, the valid measurement of degree of change becomes critical. In particular, measuring symptom change from a parents' perspective is essential, as they have the primary caretaking responsibility for their child and are optimally positioned to observe changes over time with treatment. Currently, there are no studies examining the psychometric properties of current symptom measures in evaluating symptom change associated with treatment in PBD.
Pharmacotherapy is the cornerstone of treatment for pediatric mania. The development of valid and sensitive pharmacotherapy treatment outcome measures for manic symptoms is imperative in evaluating the effectiveness of any specific medication. However, there are various barriers to accurately assessing symptom changes in PBD. First, a core feature of PBD is rapidly fluctuating mood states. Children with PBD fluctuate frequently between being irritable, sad, excitable, and elated in mood. Second, mood states tend to vary by environmental context and the presence or absence of key triggers for mood variation. These triggers are often better understood and observed by parents who see the child across multiple contexts. Third, PBD is a chronic and refractory disorder. Even when children's symptoms are effectively addressed initially, breakthrough and residual symptoms can occur with some frequency over the course of treatment. It becomes important to have accurate measures of the extent of symptoms over time to differentiate residual symptoms from acute episodes meeting full criteria. Finally, children with PBD have high rates of comorbid disorders, including Attention Deficit Hyperactivity Disorder (ADHD), Oppositional Defiant Disorder (ODD), and anxiety disorders. Comorbid symptoms, particularly those associated with ADHD, can be difficult to distinguish from PBD. This complex clinical presentation of PBD indicates the importance of developing measures that can effectively discriminate the profiles of PBD and ADHD.
These barriers to assessing symptom change associated with treatment in pediatric mania indicate that optimal treatment outcome measurement would incorporate multiple informants who could capture the child's functioning over time and across various contexts, would accurately distinguish gradations of severity in symptom experience, and would differentiate mania symptoms from co-occurring symptoms, especially ADHD. In particular, parent reports are essential as parents observe their children for extended time periods and across many contexts, which may enable them to integrate data pertinent to the child's overall level of functioning.
In addition, research evidence suggests that parent-report measures may be the most accurate in assessing pediatric mania. Youngstrom and colleagues (2005)
conducted a review of the current screening measures for pediatric mania and concluded that parent reports (which are most often mother reports) have higher diagnostic accuracy than either child or teacher reports, and that additional reporters add little utility beyond parent report. However, the authors noted that the overall predictive validity of parent-rated instruments was still modest, and thus, these measures continue to need improvement (Youngstrom, Findling, Youngstrom, & Calabrese, 2005
). Currently, the commonly used parent measures include the Child Mania Rating Scale – Parent Version (CMRS-P; Pavuluri, Henry, Devineni, Carbray, & Birmaher, 2006
), the Parent Young Mania Rating Scale (P-YMRS; Gracious, Youngstrom, Findling, & Calabrese, 2002
), and the Parent – General Behavior Inventory (P-GBI; Youngstrom, Findling, Youngstrom, & Calabrese, 2005
). Although many of these scales have been used in treatment outcome research, none of them have been specifically tested for efficacy in measuring treatment outcomes.
Of all three measures, only the CMRS-P (Pavuluri et al., 2006
) was specifically developed to address the need for a short, easily administered, comprehensive, parent-report screening and outcome measure for pediatric mania. The CMRS-P is a 21-item parent-rating scale for pediatric mania that exhibits excellent psychometric properties and accuracy in differentiating pediatric mania from ADHD. In the preliminary investigation of this measure (Pavuluri et al., 2006
), the CMRS-P demonstrated excellent internal consistency reliability, high correlations with clinician-administered interview measures for diagnosing pediatric mania (r
s = .78–.83), and an ability to accurately differentiate PBD from ADHD and healthy controls greater than 90% of the time. A brief form of the CMRS-P (10 items) was also developed and showed comparable accuracy in differentiating children with PBD from children with ADHD and healthy controls, compared to the long form (Brief CMRS-P; Henry, Pavuluri, Youngstrom, & Birmaher, 2008
). While the CMRS-P is widely used as a diagnostic screening tool in clinical work and research, neither the long form nor the brief form has been evaluated as to its validity as a measure of symptom change with treatment.
Therefore, the current study evaluated the sensitivity of the CMRS-P (both full and brief forms) to symptom change over time with treatment. The hypotheses tested were that: (1) the CMRS-P would demonstrate sensitivity to symptom change through statistically significant change from pre-treatment to post-treatment assessment; (2) change on the CMRS-P would correlate with change on the “gold standard” YMRS suggesting concurrent validity for measuring symptoms changes; and (3) changes in symptoms over the course of treatment captured by the CMRS-P would converge with response rates from other measures. If the CMRS-P proves to be a sensitive and valid instrument to measure symptom change, its broad use as an outcome measure in PBD treatment studies would be warranted and, because of its brevity and easy administration, it could be effectively incorporated into clinical practice and research as a treatment outcome indicator. Further, if both the brief and long forms are found to be sensitive to symptom change with treatment, then providers or researchers using the scale could choose the form based on their priorities (e.g. to reduce reporting burden on parents vs. acquire comprehensive symptom assessment).