Objective

Most studies of pediatric bipolar disorder (BP) combine youth who have manic symptoms, but do not meet criteria for BP I/II, into one "not otherwise specified" (NOS) group. Consequently, little is known about how youth with cyclothymic disorder (CycD) differ from youth with BP NOS. The objective of this study was to determine whether youth with a research diagnosis of CycD (RDCyc) differ from youth with operationalized BP NOS.

Method

Participants from the Course and Outcome of Bipolar Youth study were evaluated to determine whether they met RDCyc criteria. Characteristics of RDCyc youth and BP NOS youth were compared at baseline, and over eight-years follow-up.

Results

Of 154 youth (average age 11.96 (3.3), 42% female), 29 met RDCyc criteria. RDCyc youth were younger (p = .04) at baseline. Over follow-up, RDCyc youth were more likely to have a disruptive behavior disorder (p = .01), and were more likely to experience irritability (p = .03), mood reactivity (p = .02), and rejection sensitivity (p = .03). BP NOS youth were more likely to develop hypomania (p = .02), or depression (p = .02), and tended to have mood episodes earlier in the eight-year follow-up period.

Limitations

RDCyc diagnoses were made retrospectively and followed stringent criteria, which may highlight differences that, under typical clinical conditions and more vague criteria, would not be evident.

Conclusion

There were few differences between RDCyc and BP NOS youth. However, the ways in which the groups diverged could have implications; chronic subsyndromal mood symptoms may portend a severe, but ultimately non-bipolar, course. Longer follow-up is necessary to determine the trajectory and outcomes of CycD symptoms.

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.