Association between a large change between the minimum and maximum monthly values of solar insolation and a history of suicide attempts in bipolar I disorder
Authors: Ritter Philipp , 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 , Chanopoulou Margarita , Crowe Marie , Cuomo Alessandro , Dallaspezia Sara , 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 Grigorios 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. , Licht Rasmus W. , Ludwig Vera M. , 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 Alie N. R. , Meesters Ybe , Melle Ingrid , Meza-Urzúa Fátima , Michaelis Elisabeth , 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 , Pilhatsch Maximilian , Ruiz Yolanda Pica , Pinna Marco , Pompili Maurizio , Porter Richard , Quiroz Danilo , Rabelo-da-Ponte Francisco Diego , Ramesar Raj , Rasgon Natalie , Ratta-apha Woraphat , Redahan Maria , Reddy M. S. , Reif Andreas , Reininghaus Eva Z. , Richards Jenny Gringer , 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 , Volf Carlo , Yang Kai-Jie , Yoldi-Negrete Maria , Yalcinkaya Oguz Kaan , Young Allan H. , Zgueb Yosra , Whybrow Peter C. , Bauer Michael 
Published: December 2024

Abstract
Background
The rate of suicide attempts by patients with bipolar disorder is high. In addition to patient and country specific factors, environmental factors may contribute to suicidal behavior. Sunlight has multiple diverse impacts on human physiology and behavior. Solar insolation is defined as the electromagnetic energy from the sun striking a surface area on earth. We previously found that a large change in solar insolation between the minimum and maximum monthly values was associated with an increased risk of suicide attempts in patients with bipolar I disorder.

Methods
The association between solar insolation and a history of suicide attempts in bipolar disorder was again investigated using an international database with 15% more data and more sites at diverse locations and countries.

Results
Data were available from 5641 patients with bipolar I disorder living at a wide range of latitudes in 41 countries in both hemispheres. A large change in solar insolation between the minimum and maximum monthly values was associated with a history of suicide attempts in patients with bipolar I disorder, a replication of our prior analysis. The estimated model also associated state sponsored religion in the onset country, female gender, a history of alcohol or substance abuse, and being part of a younger birth cohort with a history of suicide attempts.

Conclusions
A large change between the minimum and maximum monthly values of solar insolation was associated with a history of suicide attempts in bipolar I disorder, replicating our prior research. Physicians should be aware that daylight has wide ranging physiological and psychiatric impacts, and that living with large changes in solar insolation may be associated with an increased suicide risk.