Longitudinal course and characteristics of cyclothymic disorder in youth

Abstract

Objectives Epidemiological studies suggest that cyclothymic disorder is the most prevalent subtype of bipolar disorder (BD). However, it is rarely diagnosed, especially in youth. This may be because it can be difficult to ascertain whether a youth meets diagnostic criteria. Clearer, easy-to-apply criteria could reduce misdiagnosis. The objective of this study was to determine whether proposed research diagnostic criteria for cyclothymic disorder (RDCyc), based on DSM-5 criteria, could be quantified and validated in youth. Methods Participants from the Longitudinal Assessment of Manic Symptoms (LAMS) study were recruited based on symptoms of mania and followed prospectively. RDCyc criteria were: 1) At least one core symptom each of mania and depression; 2) one additional symptom of mania and of depression; 3) persistence over two consecutive six-month periods, and 4) impairment. Exclusionary criteria were having a [hypo]manic or depressive episode. Outcomes at the two-year follow-up were compared between RDCyc youth and other diagnostic groups (BD I/II, BD NOS/non-RDCyc cyclothymic disorder, disruptive behavior disorders [DBD], depression). Results Thirty-seven youth met RDCyc criteria. There were no consistent differences between the RDCyc youth and youth with other BD subtypes (ps=.001–.960, with all-but-one p value >.02). RDCyc youth had higher depression (p<.0005) and mania scores (p=.001), lower functioning (p=.012), and higher suicide risk than DBD youth (p=.001). They had higher mania scores than depressed youth (p.018). Limitations The majority of youth in the sample were recruited due to elevated symptoms of mania, which may limit the generalizability of the results. Youth were followed for two years, which may not be long enough to determine whether or not they will eventually develop a manic or depressive episode. Conclusions Applying RDCyc criteria identified youth who were similar to others with BD and were more impaired than those with DBD. Using these criteria could reduce misdiagnosis and increase our understanding of this prevalent, but largely ignored, diagnosis.

Parsing cyclothymic disorder and other specified bipolar spectrum disorders in youth

“…Still, it is important to note that the “current” and “best” C-GAS scores across follow-up were equivalent between groups, so although those youth who experienced clinical mood episodes might experience worse functioning in the short term, both groups experienced significant impairment. This is consistent with previous studies of CycD that have shown that youth with CycD experience impairment on par with other BP youth (Van Meter et al, 2012; Van Meter, Youngstrom, Youngstrom, Feeny, & Findling, 2011; Van Meter et al, 2017).…”

“…In a previous publication examining an operationalized definition of cyclothymic disorder in youth (Van Meter et al, 2017), we applied more stringent criteria, requiring that youth be symptomatic for 44 of 52 weeks (allowing just two months total asymptomatic) and excluding any youth who experienced a mood episode ([hypo]manic or depressive) in the first year following the baseline appointment. As a sensitivity analysis, we also tested youth meeting this strict definition to the other youth in the sample.…”

“…Related, we anticipate that youth who meet the RDCyc criteria will have less intense and/or fewer manic and depressive symptoms than youth with BP NOS, but that the RDCyc youth will be equally impaired due to the chronicity of their symptoms. Additionally, we expect that RDCyc youth will differ from BP NOS youth on the following baseline characteristics: family history of psychopathology (RDCyc will have higher prevalence of non-mood psychiatric illness, but no difference in family history of mania or depression; Van Meter et al, 2012; Van Meter et al, 2011) and medication (although in a previous study, there were no statistical differences, more than twice as many youth in the BP NOS group took a mood stabilizer, and 17% more took an antipsychotic than in the RDCyc group (Van Meter et al, 2017), consequently we expect the RDCyc youth to be less likely to be prescribed lithium or a mood stabilizer). We anticipate that the RDCyc and BP NOS youth will have similar age of BP onset (Van Meter et al, 2012; Van Meter et al, 2011), rates of comorbid disorders, consistent with previous research on both adults and children (Van Meter et al, 2012; Van Meter, Youngstrom, & Findling, 2012), and rates of suicidal ideation and behavior (Van Meter et al, 2017).…”

“…On the other hand, youth with CycD experience chronic symptoms lasting at least a year. This chronicity may ultimately lead to impairment on par with the more intense symptoms experienced by youth with other subtypes of BP (Van Meter et al, 2017). It is also possible that this more chronic presentation portends a different life course, such as borderline personality disorder (BPD), which shares many features with CycD (Reich, Zanarini, & Fitzmaurice, 2011).…”

“…We hypothesize that across the follow-up period, RDCyc youth will be less likely to experience a mood episode than the BP NOS youth (Van Meter et al, 2017). Related, we anticipate that youth who meet the RDCyc criteria will have less intense and/or fewer manic and depressive symptoms than youth with BP NOS, but that the RDCyc youth will be equally impaired due to the chronicity of their symptoms.…”