Cyclothymic disorder also referred to as cyclothymia, is a subtype of bipolar disorder. More specifically, cyclothymic disorder is defined as instability of mood, with regular mood swings from hypomania to depression. This particular subtype of bipolar disorder is more prevalent than bipolar type I and type II disorders. 

According to a survey, 2.4% of adults are living with cyclothymic disorder. Some research suggests that people who have cyclothymic disorder have an increased chance of developing bipolar I or bipolar II disorder. Another study notes that cyclothymic disorder is understudied despite the evidence that 30–50% of people with depression, anxiety, borderline personality disorder and other personality disorders may also have a co-occurring cyclothymic disorder. For more information about cyclothymic disorder and related topics, explore the following articles.