Exploratory study of ultraviolet B (UVB) radiation and age of onset of bipolar disorder
Authors: Bauer Michael , Glenn Tasha , Achtyes Eric D. , Alda Martin , Agaoglu Esen , Altınbaş Kürsat , Andreassen Ole A. , Angelopoulos Elias , Ardau Raffaella , Aydin Memduha , Ayhan Yavuz , Baethge Christopher , Bauer Rita , Baune Bernhard T. , Balaban Ceylan , Becerra-Palars Claudia , Behere Aniruddh P. , Behere Prakash B. , Belete Habte , Belete Tilahun , Belizario Gabriel Okawa , Bellivier Frank , Belmaker Robert H. , Benedetti Francesco , Berk Michael , Bersudsky Yuly , Bicakci Şule , Birabwa-Oketcho Harriet , Bjella Thomas D. , Brady Conan , Cabrera Jorge , Cappucciati Marco , Castro Angela Marianne Paredes , Chen Wei-Ling , Cheung Eric Y. W. , Chiesa Silvia , Crowe Marie , Cuomo Alessandro , Dallaspezia Sara , Del Zompo Maria , Desai Pratikkumar , Dodd Seetal , Etain Bruno , Fagiolini Andrea , Fellendorf Frederike T. , Ferensztajn-Rochowiak Ewa , Fiedorowicz Jess G. , Fountoulakis Kostas N. , Frye Mark A. , Geoffroy Pierre A. , Gitlin Michael J. , Gonzalez-Pinto Ana , Gottlieb John F. , Grof Paul , Haarman Bartholomeus C. M. , Harima Hirohiko , Hasse-Sousa Mathias , Henry Chantal , Hoffding Lone , Houenou Josselin , Imbesi Massimiliano , Isometsä Erkki T. , Ivkovic Maja , Janno Sven , Johnsen Simon , Kapczinski Flávio , Karakatsoulis Gregory N. , Kardell Mathias , Kessing Lars Vedel , Kim Seong Jae , König Barbara , Kot Timur L. , Koval Michael , Kunz Mauricio , Lafer Beny , Landén Mikael , Larsen Erik R. , Lenger Melanie , Licht Rasmus W. , Lopez-Jaramillo Carlos , MacKenzie Alan , Madsen Helle Østergaard , Madsen Simone Alberte Kongstad A. , Mahadevan Jayant , Mahardika Agustine , Manchia Mirko , Marsh Wendy , Martinez-Cengotitabengoa Monica , Martini Julia , Martiny Klaus , Mashima Yuki , McLoughlin Declan M. , Meesters Ybe , Melle Ingrid , Meza-Urzúa Fátima , Mikolas Pavol , Mok Yee Ming , Monteith Scott , Moorthy Muthukumaran , Morken Gunnar , Mosca Enrica , Mozzhegorov Anton A. , Munoz Rodrigo , Mythri Starlin V. , Nacef Fethi , Nadella Ravi K. , Nakanotani Takako , Nielsen René Ernst , O’Donovan Claire , Omrani Adel , Osher Yamima , Ouali Uta , Pantovic-Stefanovic Maja , Pariwatcharakul Pornjira , Petite Joanne , Petzold Johannes , Pfennig Andrea , Ruiz Yolanda Pica , Pinna Marco , Pompili Maurizio , Porter Richard J. , Quiroz Danilo , Rabelo-da-Ponte Francisco Diego , Ramesar Raj , Rasgon Natalie , Ratta-apha Woraphat , Ratzenhofer Michaela , Redahan Maria , Reddy M. S. , Reif Andreas , Reininghaus Eva Z. , Richards Jenny Gringer , Ritter Philipp , Rybakowski Janusz K. , Sathyaputri Leela , Scippa Angela M. , Simhandl Christian , Smith Daniel , Smith José , Stackhouse Paul W. , Stein Dan J. , Stilwell Kellen , Strejilevich Sergio , Su Kuan-Pin , Subramaniam Mythily , Sulaiman Ahmad Hatim , Suominen Kirsi , Tanra Andi J. , Tatebayashi Yoshitaka , Teh Wen Lin , Tondo Leonardo , Torrent Carla , Tuinstra Daniel , Uchida Takahito , Vaaler Arne E. , Vieta Eduard , Viswanath Biju , Yoldi-Negrete Maria , Yalcinkaya Oguz Kaan , Young Allan H. , Zgueb Yosra , Whybrow Peter C. 
Published: June 2023

Abstract
Background
Sunlight contains ultraviolet B (UVB) radiation that triggers the production of vitamin D by skin. Vitamin D has widespread effects on brain function in both developing and adult brains. However, many people live at latitudes (about > 40 N or S) that do not receive enough UVB in winter to produce vitamin D. This exploratory study investigated the association between the age of onset of bipolar I disorder and the threshold for UVB sufficient for vitamin D production in a large global sample.

Methods
Data for 6972 patients with bipolar I disorder were obtained at 75 collection sites in 41 countries in both hemispheres. The best model to assess the relation between the threshold for UVB sufficient for vitamin D production and age of onset included 1 or more months below the threshold, family history of mood disorders, and birth cohort. All coefficients estimated at P ≤ 0.001.

Results
The 6972 patients had an onset in 582 locations in 70 countries, with a mean age of onset of 25.6 years. Of the onset locations, 34.0% had at least 1 month below the threshold for UVB sufficient for vitamin D production. The age of onset at locations with 1 or more months of less than or equal to the threshold for UVB was 1.66 years younger.

Conclusion
UVB and vitamin D may have an important influence on the development of bipolar disorder. Study limitations included a lack of data on patient vitamin D levels, lifestyles, or supplement use. More study of the impacts of UVB and vitamin D in bipolar disorder is needed to evaluate this supposition.