Examining the validity of cyclothymic disorder in a youth sample: Replication and extension

Four subtypes of bipolar disorder (BP) – bipolar I, bipolar II, cyclothymia and bipolar not otherwise specified (NOS) – are defined in DSM-IV-TR. Though the diagnostic criteria for each subtype are intended for both adults and children, research investigators and clinicians often stray from the DSM when diagnosing pediatric bipolar disorder (PBD) (Youngstrom, 2009), resulting in a lack of agreement and understanding regarding the PBD subtypes