Generalizability of Evidence-Based Assessment Recommendations for Pediatric Bipolar Disorder.

Bipolar disorder is a high stakes diagnosis. Untreated, it often follows a recurrent and progressively worsening course, with increased risk of substance use, incarceration, and death by suicide or other causes (Goodwin & Jamison, 2007). If bipolar is misdiagnosed as depression or attention-deficit/hyperactivity disorder, there are delays initiating effective mood stabilizing treatments (Kowatch, Fristad, et al., 2005). There also are concerns that the options selected instead could worsen the course of the bipolar disorder (Akiskal, et al., 2003; Altshuler, et al., 1995; cf. Carlson, 2003; Hirschfeld, et al., 2002; cf. Joseph, Youngstrom, & Soares, 2009; Scheffer, Kowatch, Carmody, & Rush, 2005). Earlier identification may lead to better outcomes (DelBello, Adler, Whitsel, Stanford, & Strakowski, 2007; Findling, et al., 2003; Fristad, Verducci, Walters, & Young, 2009), delay or prevent relapse (Findling, et al., 2007), and afford more titrated or benign interventions (Miklowitz & Chang, 2008). The median lag exceeds five years between when mood symptoms begin to cause problems versus when a clinician arrives at a bipolar diagnosis in youths (Marchand, Wirth, & Simon, 2006) as well as adults (Hirschfeld, Lewis, & Vornik, 2003; Lish, Dime-Meenan, Whybrow, Price, & Hirschfeld, 1994). To close this gap, early identification has been promoted both in scholarly research (Miklowitz & Chang, 2008; Youngstrom, Findling, Youngstrom, & Calabrese, 2005) and in the popular media (Kluger & Song, 2002; Papolos & Papolos, 2002). There is concern that the pendulum may have swung too far in favor of early diagnosis, though (Healy, 2006; Parens, Johnston, & Carlson, 2010). Clinical diagnoses of pediatric bipolar disorder (PBD) have risen steeply in the U.S. (Blader & Carlson, 2007), with some estimates showing a 40-fold increase in diagnoses over the last decade (Moreno, et al., 2007). Although evidence supports the validity of research diagnoses of bipolar disorder in terms of phenotypic, genetic, structural, functional, neurocognitive, and treatment response similarities to bipolar disorder in adults (Geller & Luby, 1997; Youngstrom, Birmaher, & Findling, 2008); and longitudinal studies are demonstrating considerable developmental continuity (Birmaher, et al., 2009; Geller, Tillman, Bolhofner, & Zimerman, 2008), the crucial issue from a public health and consumer point of view is whether the research diagnoses and clinical diagnoses identify the same cases. Clinical diagnosis itself is a complex enterprise, fraught with potential biases and sources of error (Garb, 1998). Clinicians tend to rely on unstructured interviews and observations that have proven problematic (Neisworth & Bagnato, 2004). Clinicians also are prone to cognitive biases that often result in suboptimal diagnostic decisions (Croskerry, 2002; Galanter & Patel, 2005). More than 100 studies over the last 50 years have consistently demonstrated that clinical judgment is no better than simple actuarial algorithms, and often significantly worse (AEgisdottir, et al., 2006; Grove, Zald, Lebow, Snitz, & Nelson, 2000; Meehl, 1954). The situation appears even worse with regard to clinical diagnoses of bipolar disorder. A recent meta-analysis comparing clinical diagnoses to those based on structured interviews found that bipolar disorder was an outlier even compared to the general trend of mediocrity in diagnostic reliability, with a kappa of less than .10 (Rettew, Lynch, Achenbach, Dumenci, & Ivanova, 2009). Unfortunately, it is also very difficult to assess because of the phenomenology of the illness (Bowring & Kovacs, 1992; Youngstrom, Findling, et al., 2005) as there is substantial overlap in symptomatology (Leibenluft, Charney, Towbin, Bhangoo, & Pine, 2003; Weller, Danielyan, & Weller, 2004) making it hard to tease apart bipolar symptoms from symptoms of more prevalent diagnoses, such as Attention Deficit Hyperactivity Disorder (ADHD). In addition, comorbidity complicates diagnosis, as youths frequently meet criteria for multiple psychiatric disorders (Axelson, et al., 2006; Kowatch, Youngstrom, Danielyan, & Findling, 2005). Consequently, a “typical” presentation of bipolar in isolation is rare, and clinicians may focus on the comorbid condition and neglect PBD (Youngstrom, Findling, et al., 2005). Further, varied presentations of PBD threaten the reliability of diagnostic impressions. For example, classic bipolar I disorder can present as florid mania, severe depression, a mixed state, or as normal functioning, depending on the mood state. In addition to PBD being arguably one of the most difficult diagnoses to make correctly, broader practice issues of training, burden, and reimbursement can make research diagnostic instruments, such as structured and semi-structured interviews, impractical for use in many clinical settings. As a result, many common assessment methods are not evidence-based (EB). Thus, the difficulty diagnosing PBD is compounded by complex presentation of illness, contextual constraints common to real-world clinical practice, and clinicians’ cognitive vulnerabilities. Clinical diagnoses of bipolar disorder in adults also have waxed and waned in popularity, without any evidence of a corresponding change in the base rate of the condition (Zuckerman, 1999). There is debate about whether the contemporary rise in clinical diagnoses is a correction from previous underdiagnosis—similar to historical changes in patterns of diagnosis for depression (Kovacs, 1989), versus being evidence of overdiagnosis, perhaps due to nonspecific use of the “bipolar” label to include a broad group of youths who have marked irritability and aggression, but may not otherwise meet criteria for mania (Leibenluft, et al., 2003). Overall, it appears many youth diagnosed with bipolar do not actually have the disorder while many true cases of bipolar go undiagnosed (Ghaemi, Sachs, Chiou, Pandurangi, & Goodwin, 1999).