The International Society for Bipolar Disorders Task Force report on pediatric bipolar disorder: Knowledge to date and directions for future research

OBJECTIVES

Over the past two decades, there has been tremendous growth in research regarding bipolar disorder (BD) among children and adolescents (ie, pediatric BD [PBD]). The primary purpose of this article is to distill the extant literature, dispel myths or exaggerated assertions in the field, and disseminate clinically relevant findings.

METHODS

An international group of experts completed a selective review of the literature, emphasizing areas of consensus, identifying limitations and gaps in the literature, and highlighting future directions to mitigate these gaps.

RESULTS

Substantial, and increasingly international, research has accumulated regarding the phenomenology, differential diagnosis, course, treatment, and neurobiology of PBD. Prior division around the role of irritability and of screening tools in diagnosis has largely abated. Gold-standard pharmacologic trials inform treatment of manic/mixed episodes, whereas fewer data address bipolar depression and maintenance/continuation treatment. Adjunctive psychosocial treatment provides a forum for psychoeducation and targets primarily depressive symptoms. Numerous neurocognitive and neuroimaging studies, and increasing peripheral biomarker studies, largely converge with prior findings from adults with BD.

CONCLUSIONS

As data have accumulated and controversy has dissipated, the field has moved past existential questions about PBD toward defining and pursuing pressing clinical and scientific priorities that remain. The overall body of evidence supports the position that perceptions about marked international (US vs elsewhere) and developmental (pediatric vs adult) differences have been overstated, although additional research on these topics is warranted. Traction toward improved outcomes will be supported by continued emphasis on pathophysiology and novel therapeutics.

An Independent Confirmatory Factor Analysis of the Differential Ability Scales

This study investigated the structure of the Differential Ability Scales (DAS; Elliott, 1990a) using confirmatory factor analysis with 130 normal school-aged children. Maximum likelihood estimation, using the six Core subtests, found an extremely good fit with the data and supported the DAS model proposed by Elliott (1990a). In addition, the six Core subtests were found to be strong measures of g, supporting their contribution to the General Conceptual Ability. Replication of Keith's (1990) final model, which included the six Core subtests and three Diagnostic subtests, was also conducted. This model was based on the same theoretical framework against which Keith (1990) tested his models. This theoretical framework was derived from a logical analysis of the nature of the subtests in light of prior research. The present study found a reasonably good fit for the data when the model included both the Core and Diagnostic subtests.

WISC-IV and WIAT-II Profiles in Children With High-Functioning Autism

Children with high-functioning autism earned above normal scores on the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) Perceptual Reasoning and Verbal Comprehension Indexes and below normal scores on the Working Memory and Processing Speed Indexes and Wechsler Individual Achievement Test-Second Edition (WIAT-II) Written Expression. Full Scale IQ (FSIQ) and reading and math scores were similar to the norm. Profiles were consistent with previous WISC-III research, except that the new WISC-IV motor-free visual reasoning subtests (Matrix Reasoning and Picture Concepts) were the highest of the nonverbal subtests. The WISC-IV may be an improvement over the WISC-III for children with high-functioning autism because it captures their visual reasoning strength, while identifying their attention, graphomotor, and processing speed weaknesses. FSIQ was the best single predictor of academic achievement.

A nationwide epidemiologic modeling study of LD: risk, protection, and unintended impact

Through multiple logistic regression modeling, this article explores the relative importance of risk and protective factors associated with learning disabilities (LD). A representative national sample of 6- to 17-year-old students (N = 1,268) was drawn by random stratification and classified by the presence versus absence of LD in reading, spelling, and mathematics according to ability-achievement discrepancies or low achievement levels. The dichotomous classifications were regressed on sets of explanatory variables indicating potential biological, social-environmental, and cognitive factors, problem behavior, and classroom learning behavior. Modeling revealed patterns of high risk for male students and students evincing verbal and nonverbal ability problems and processing speed problems. It was shown that, absent controls for cognitive abilities (such as provided by the ability-achievement discrepancy definition), definitions keyed to low achievement will substantially overidentify ethnic minority and disadvantaged students and will be confounded by significantly higher proportions of students who display oppositional and aggressive behavior problems. Alternatively, good learning behaviors uniformly provide substantial reduction in the risk for LD.

WISC-IV and WISC-III profiles in children with ADHD

Wechsler Intelligence Scale for Children, 3rd and 4th editions (WISC-III n = 586 and WISC-IV n = 118), profiles were compared for children with ADHD and normal intelligence. Mean Verbal Comprehension Index (VCI) and Perceptual Organization/Perceptual Reasoning Index (POI/PRI) scores were significantly higher than Freedom From Distractibility/Working Memory Index (FDI/WMI) and Processing Speed Index (PSI), and Symbol Search was higher than Coding. FDI/WMI and PSI scores were similar on both tests, but VCI and POI/PRI were higher on the WISC-IV than on the WISC-III. Therefore, index discrepancies were greater for the WISC-IV, suggesting that the WISC-IV might be better than the WISC-III in delineating the strengths and weaknesses of children with ADHD. All children in the WISC-IV sample scored lowest on WMI or PSI, whereas only 88% of the WISC-III children scored lowest on FDI or PSI. Thus, the WISC-IV may be more helpful in diagnosing ADHD than the WISC-III.

Similarities and differences in Wechsler Intelligence Scale for Children--Third Edition (WISC-III) profiles: support for subtest analysis in clinical referrals

Our study supports the reliability and validity of profile analysis in children with neurobiological disorders. Three mutually exclusive WISC-III profiles were identified that characterized the majority of children with autism (low coding or Freedom from Distractibility Index with low Comprehension), attention deficit hyperactivity disorder and learning disability (low Coding or FDI without low comprehension), and brain injury (low Performance without low Coding or FDI). The profiles suggest attention, writing, and performance speed deficits in autism, ADHD, and LD; global visual-motor problems in brain injury; and specific difficulty with language comprehension and social reasoning in autism. Children with anxiety, depression, and behavior disorders did not exhibit distinct profiles. Our profile analysis is based on the simple rank ordering of standard scores. The profiles are clinically useful because they may alert clinicians to certain diagnostic possibilities, they reveal characteristic strengths and weaknesses that have implications for educational intervention, and they are consistent with preliminary WISC-IV data.