Cyclothymic disorder in youth: why is it overlooked, what do we know and where is the field headed?

Parsing cyclothymic disorder and other specified bipolar spectrum disorders in youth

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.

Longitudinal course and characteristics of cyclothymic disorder in youth

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 oftable 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=0.001-0.960, with all-but-one p value >0.02). RDCyc youth had higher depression (p<0.0005) and mania scores (p=0.001), lower functioning (p=0.012), and higher suicide risk than DBD youth (p=0.001). 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.

Impact of Irritability and Impulsive Aggressive Behavior on Impairment and Social Functioning in Youth with Cyclothymic Disorder

OBJECTIVE

Research on adults with cyclothymic disorder (CycD) suggests that irritability and impulsive aggression (IA) are highly prevalent among this population. Less is known about whether these behaviors might also distinguish youth with CycD from youth without CycD. Additionally, little is known about how irritability and IA relate to one another, and whether they are associated with different outcomes. This study aimed to compare irritability and IA across diagnostic subtypes to determine whether CycD is uniquely associated with these behaviors, and to assess how irritability and IA relate to youth social and general functioning.

METHODS

Participants (n = 459), 11-18 years of age, were recruited from an urban community mental health center and an academic outpatient clinic; 25 had a diagnosis of CycD. Youth and caregivers completed measures of IA and irritability. Youth and caregivers also completed an assessment of youth friendship quality. Clinical interviewers assessed youth social, family, and school functioning.

RESULTS

Youth with CycD had higher scores on measures of irritability and IA than youth with nonbipolar disorders, but scores were not different from other youth with bipolar spectrum disorders. Measures of irritability and IA were correlated, but represented distinct constructs. Regression analyses indicated that irritability was related to friendship quality (p < 0.005). Both IA and irritability were related to social impairment (ps < 0.05-0.0005) and Child Global Assessment Scale (C-GAS) scores (ps = 0.05-0.005). CycD diagnosis was associated with poorer caregiver-rated friendship quality and social functioning (ps < 0.05).

CONCLUSIONS

We found that irritability and aggression were more severe among youth with CycD than among youth with nonbipolar diagnoses, but did not differ across bipolar disorder subtypes. Among youth seeking treatment for mental illness, irritability and IA are prevalent and nonspecific. Irritability and IA were uniquely related to our outcomes of social and general functioning, suggesting that it is worthwhile to assess each separately, in order to broaden our understanding of the characteristics and correlates of each.

Distinguishing bipolar disorder from other psychiatric disorders in children

Pediatric onset bipolar disorder (BD) is a challenging diagnosis with potentially debilitating outcomes. This review aims to critically evaluate recently published literature relevant to the diagnosis of BD in youth, emphasizing interesting and important new findings characterizing pediatric BD and reporting updates in the diagnostic and statistical manual relevant to this disorder in youth. Challenges regarding the diagnosis of BD will be discussed, in addition to important distinctions with other childhood disorders, including other bipolar spectrum disorders; major depressive disorder; dysthymia; disruptive mood dysregulation disorder (DMDD); attention-deficit/hyperactivity disorder (ADHD) and other disruptive behavioral disorders; anxiety disorders, including post-traumatic stress disorder (PTSD); psychotic disorders; autism spectrum disorders; substance use disorders; and borderline personality disorder. The review concludes with a comment on past research limitations and future directions in the field.