Examining the Validity of Cyclothymic Disorder in a Youth Sample: Replication and Extension

DSM-IV-TR defines four subtypes of bipolar disorder (BP): bipolar I, bipolar II, cyclothymic disorder and bipolar not otherwise specified (NOS). However, cyclothymic disorder in children is rarely researched, or often subsumed in an “NOS” category. The present study tests the replicability of findings from an earlier study, and expands on the criterion validity of cyclothymic disorder in youth. Using the Robins and Guze (1970) framework we examined the validity of cyclothymic disorder as a subtype of BP. Using a youth (ages 5–17) outpatient clinical sample (N?=?894), participants with cyclothymic disorder (n?=?53) were compared to participants with other BP spectrum disorders (n?=?399) and to participants with non-bipolar disorders (n?=?442). Analyses tested differences in youth with cyclothymic disorder and bipolar disorder not otherwise specified who do, and those who do not, have a parent with BP. Compared to youth with non-bipolar disorders, youth with cyclothymic disorder had higher irritability (p?<?0.001), more comorbidity (p?<?0.001), greater sleep disturbance (p?<?0.005), and were more likely to have a family history of BP (p?<?0.001). Cyclothymic disorder was associated with a younger age of onset compared to depression (p?<?0.001) and bipolar II (p?=?0.05). Parental BP status was not significantly associated with any variables. Results support that cyclothymic disorder belongs on the bipolar spectrum. Epidemiological studies indicate that cyclothymic disorder is not uncommon and involves significant impairment. Failing to differentiate between cyclothymic disorder and bipolar NOS limits our knowledge about a significant proportion of cases of bipolarity.     

Structure and measurement of depression in youths: applying item response theory to clinical data

Our goals in this article were to use item response theory (IRT) to assess the relation of depressive symptoms to the underlying dimension of depression and to demonstrate how IRT-based measurement strategies can yield more reliable data about depression severity than conventional symptom counts. Participants were 3,403 children and adolescents from 12 contributing clinical and nonclinical samples; all participants had received the Kiddie Schedule of Affective Disorders and Schizophrenia for School-Aged Children. Results revealed that some symptoms reflected higher levels of depression and were more discriminating than others. Furthermore, use of IRT-based information about symptom severity and discriminability in the measurement of depression severity was shown to reduce measurement error and increase measurement fidelity.     

Early-Onset Bipolar Spectrum Disorders: Diagnostic Issues

Since the mid 1990s, early-onset bipolar spectrum disorders (BPSDs) have received increased attention in both the popular press and scholarly press. Rates of diagnosis of BPSD in children and adolescents have increased in inpatient, outpatient, and primary care settings. BPSDs remain difficult to diagnose, particularly in youth. The current diagnostic system makes few modifications to accommodate children and adolescents. Researchers in this area have developed specific BPSD definitions that affect the generalizability of their findings to all youth with BPSD. Despite knowledge gains from the research, BPSDs are still difficult to diagnose because clinicians must: (1) consider the impact of the child’s developmental level on symptom presentation (e.g., normative behavior prevalence, environmental limitations on youth behavior, pubertal status, irritability, symptom duration); (2) weigh associated impairment and course of illness (e.g., neurocognitive functioning, failing to meet full DSM criteria, future impairment); and (3) make decisions about appropriate assessment (differentiating BPSD from medical illnesses, medications, drug use, or other psychiatric diagnoses that might better account for symptoms; comorbid disorders; informant characteristics and assessment measures to use). Research findings concerning these challenges and relevant recommendations are offered. Areas for further research to guide clinicians’ assessment of children with early-onset BPSD are highlighted. Principal Investigators and Coinvestigators of Longitudinal Assessment of Manic Symptoms (LAMS) Group are listed in Appendix.     

Who are the comorbid adolescents? Agreement between psychiatric diagnosis,youth, parent,and teacher report

The investigators examined the rates of psychiatric comorbidity for externalizing and internalizing behavior problems, using semistructured diagnostic interview and parent, teacher, and youth report on the Achenbach checklists. The study also evaluated the effects of conjunctive, compensatory, and disjunctive data combination strategies. Using the same data and identical diagnostic thresholds, between 5 and 74% of 189 youths presenting to an outpatient clinic were identified as having comorbid internalizing and externalizing problems. Parent report and semistructured interview indicated the highest comorbidity rates. Despite good cross-source agreement (rs .29–.58), there was very little agreement about which specific youths presented with comorbid internalizing and externalizing problems (kappas .14–.40). Results also indicate that single DSM-IV disorders, such as bipolar disorder, can manifest comorbid patterns of behavior problems on checklists.