Bipolar disorder in the International Classification of Diseases-Eleventh version: A review of the changes, their basis, and usefulness

Table 6 Changes to the diagnostic guidelines in the International Classification of Diseases, 11^th version for cyclothymic disorder

	ICD-11-CDDR	DSM-5	ICD-10
Core features	Chronic mood instability of more than two years consisting of several hypomanic and depressive periods (irritability in children and adolescents)	Several hypomanic or depressive symptoms for more than two years	A persistent instability of mood, involving numerous periods of mild depression and mildelation (No duration mentioned)
	Hypomanic symptoms may meet the criteria for hypomanic episodes	Symptoms do not meet the criteria for hypomanic or major depressive episodes	None of these symptoms meet criteria for mania/BD or depressive episode/recurrent depressive disorder
Symptom-free periods	Symptom-free periods are no longer than two months during the course of the disorder	Hypomanic and depressive symptoms are present at least half of the time during the course of the disorder	Mood state may be normal and stable for months (No minimum duration for symptom-free periods specified)
		Symptom-free periods are no longer than two months during this period
Children and adolescents	Duration of one year is appropriate	Duration of one year sufficient	No mention of duration in children and adolescents
Manic mixed, and depressive episodes	Criteria for manic and mixed episodes are never met. Depressive episodes cannot be diagnosed during the first two years of cyclothymia. After that, they can be diagnosed if criteria are met	Criteria for manic, hypomanic, or major depressive episodes are never met during the first 2 years. If the person subsequently experiences major depression, mania, or hypomania, the diagnosis is changed to major depressive disorder, BP-I disorder, or other specified or unspecified bipolar and related disorders	Criteria for manic, mixed, and depressive episodes are never met
	Criteria for BP-I or BP-II disorder are never met		Criteria for BD or recurrent depressive disorder are never met
Exclusions	Cyclothymia secondary to medical conditions or substance use	Cyclothymia secondary to medical conditions or substance use	No exclusions
Functional impairment	Symptoms result in significant distress and/or functional impairment	Symptoms result in significant distress and/or functional impairment	Symptoms are so mild that patients often do not seek treatment
Progression to BD	Mentioned	Mentioned	Mentioned
Inclusion of additional personality features	Not included-unlike personality disorders, cyclothymia does not include persistent self and interpersonal dysfunction	Included-the person may be temperamental, moody, unpredictable, inconsistent, or unreliable	Included-in some instances, mood changes are less prominent than cyclical disturbances of activity, self-confidence, and social behaviour

BP-I: Type I bipolar disorder; BP-II: Type II bipolar disorder; DSM-5: Diagnostic and Statistical Manual of Mental Disorders, 5^th edition[6]; ICD-10: International Classification of Diseases, 10^th version[14]; ICD-11-CDDR: International Classification of Diseases, 11^th version, Clinical Descriptions and Diagnostic Requirements[8].