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

Table 3 Prevalence of bipolar disorder according to the International Classification of Diseases, 11^th version and the Diagnostic and Statistical Manual of Mental Disorder, 5^th edition criteria

Ref.	Criteria sets	Patients	Bipolar types	Type of prevalence	Results regarding the prevalence of BD
No change in the prevalence of bipolar disorder
Fassassi et al[55], 2014	DSM-5	Community-based	BP-I, BP-II, Other BD1	12-mo and lifetime	Prevalence similar to earlier studies of BD
Calvó-Perxas et al[56], 2015	DSM-5	Community-based	BP-I, BP-II, Other BD	Lifetime	Prevalence was within the range of previous reports of BD
Blanco et al[57], 2017	DSM-5	Community-based	BP-I	Lifetime	Prevalence was within the range of previous reports of BD
Gordon-Smith et al[58], 2017	DSM-IV and DSM-5	Community-based and outpatients	BP-I, BP-II	Lifetime	Up to 94% of the patients with DSM-IV BD also met the DSM-5 criteria
Decrease in the prevalence of bipolar disorder
Angst et al[53], 20132	DSM-5	Analysis based on a previous community study (BRIDGE)	BD	Lifetime	About 22% reduction in prevalence
Machado-Vieira et al[38], 2017	DSM-IV and DSM-5	Outpatients	Maniaand hypomania	Point prevalence	The prevalence of mania and hypomania according to the DSM-5 criteria was reduced by about 50%
Fredskild et al[59], 2019	DSM-IV TR and DSM-5	Outpatients	Maniaand hypomania	Point prevalence	A reduction of 35% in the prevalence of mania and hypomania with the DSM-5 criteria was noted
Faurholt-Jepsen et al[60], 2020	DSM-5	Patients taking part in trials	Mania and hypomania	Smartphone-based activity assessments over 6-9 mo	The prevalence of hypomania according to the DSM-5 criteria was substantially less (0.12%) than patients not meeting these criteria (24%)
Fredskild et al[61], 2021	DSM-IVand DSM-5	Outpatients	Mania and hypomania	Assessments at baseline and at 3-year follow-up	The prevalence of mania and hypomania according to the DSM-5 criteria was reduced by 62% at baseline and by 50% on follow-up
Increase in the prevalence of type II bipolar disorder
Angst et al[53], 20133	DSM-5	Analysis based on a previous community study (BRIDGE)	BP-II	Lifetime	Prevalence of BP-II disorder will be twice as much with the DSM-5 than earlier
Angst et al[31], 20204	ICD-10, DSM-5, and ICD-11	Analysis based on an earlier community study (Zurich cohort study)	Mania (BP-I) and hypomania (BP-II)	Lifetime	Prevalence of hypomania (BP-II) will be doubled with the ICD-11 criteria compared to the ICD-10 and the DSM-5 criteria; no change in the prevalence of mania (BP-I) is likely

¹The Other BD group refers to the “Other Specified Bipolar and Related Disorders” category of the DSM-5.

²This reduction is proposed to be a consequence of the mandatory requirement for both mood changes and overactivity.

³The increase in prevalence is proposed to be a consequence of inclusion of patients with antidepressant-induced prolonged hypomanic switches.

⁴The increase in prevalence is proposed to be a consequence of a somewhat broader definition of hypomania in the ICD-11 and the inclusion of patients with antidepressant-induced prolonged hypomanic switches.

BD: Bipolar disorder; BP-I: Type I bipolar disorder; BP-II: Type II bipolar disorder; BRIDGE: Bipolar disorders: Improving diagnosis, Guidance, and Education[49]; DSM-IV/DSM-IV TR: Diagnostic and Statistical Manual of Mental Disorders, 4^th edition/Text revision[62,63]; 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: International Classification of Diseases, 11^th version[8].