Citation

Bauer M, Glenn T, Achtyes ED, Alda M, Agaoglu E, Altınbaş K, Andreassen OA, Angelopoulos E, Ardau R, Vares EA, Aydın M, Ayhan Y, Baethge C, Bauer R, Baune BT, Balaban C, Becerra-Palars C, Behere AP, Behere PB, Belete H, Belete T, Belizario GO, Bellivier F, Belmaker RH, Benedetti F, Berk M, Bersudsky Y, Bicakci, Birabwa-Oketcho H, Bjella TD, Brady C, Cabrera J, Cappucciati M, Castro AMP, Chen WL, Cheung EYW, Chiesa S, Crowe M, Cuomo A, Dallaspezia S, Del Zompo M, Desai P, Dodd S, Donix M, Etain B, Fagiolini A, Fellendorf FT, Ferensztajn-Rochowiak E, Fiedorowicz JG, Fountoulakis KN, Frye MA, Geoffroy PA, Gonzalez-Pinto A, Gottlieb JF, Grof P, Haarman BCM, Harima H, Hasse-Sousa M, Henry C, Høffding L, Houenou J, Imbesi M, Isometsä ET, Ivković M, Janno S, Johnsen S, Kapczinski F, Karakatsoulis GN, Kardell M, Kessing LV, Kim SJ, König B, Kot TL, Koval M, Kunz M, Lafer B, Landén M, Larsen ER, Lenger M, Lewitzka U, Licht RW, Lopez-Jaramillo C, MacKenzie A, Madsen H, Madsen SAKA, Mahadevan J, Mahardika A, Manchia M, Marsh W, Martinez-Cengotitabengoa M, Martiny K, Mashima Y, McLoughlin DM, Meesters Y, Melle I, Meza-Urzúa F, Ming MY, Monteith S, Moorthy M, Morken G, Mosca E, Mozzhegorov AA, Munoz R, Mythri SV, Nacef F, Nadella RK, Nakanotani T, Nielsen RE, O'Donovan C, Omrani A, Osher Y, Ouali U, Pantović-Stefanović M, Pariwatcharakul P, Petite J, Pfennig A, Ruiz YP, Pilhatsch M, Pinna M, Pompili M, Porter R, Quiroz D, Rabelo-da-Ponte FD, Ramesar R, Rasgon N, Ratta-Apha W, Ratzenhofer M, Redahan M, Reddy MS, Reif A, Reininghaus EZ, Richards JG, Ritter P, Rybakowski JK, Sathyaputri L, Scippa M, Simhandl C, Severus E, Smith D, Smith J, Stackhouse PWJ, Stein DJ, Stilwell K, Strejilevich S, Su KP, Subramaniam M, Sulaiman AH, Suominen K, Tanra AJ, Tatebayashi Y, Teh WL, Tondo L, Torrent C, Tuinstra D, Uchida T, Vaaler AE, Veeh J, Vieta E, Viswanath B, Yoldi-Negrete M, Yalcinkaya OK, Young AH, Zgueb Y, Whybrow PC. Int. J. Bipolar Disord. 2021; 9(1): e26.

Copyright

(Copyright © 2021, Holtzbrinck Springer Nature Publishing Group)

DOI

10.1186/s40345-021-00231-7

PMID

unavailable

Abstract

BACKGROUND: Bipolar disorder is associated with circadian disruption and a high risk of suicidal behavior. In a previous exploratory study of patients with bipolar I disorder, we found that a history of suicide attempts was associated with differences between winter and summer levels of solar insolation. The purpose of this study was to confirm this finding using international data from 42% more collection sites and 25% more countries.

METHODS: Data analyzed were from 71 prior and new collection sites in 40 countries at a wide range of latitudes. The analysis included 4876 patients with bipolar I disorder, 45% more data than previously analyzed. Of the patients, 1496 (30.7%) had a history of suicide attempt. Solar insolation data, the amount of the sun's electromagnetic energy striking the surface of the earth, was obtained for each onset location (479 locations in 64 countries).

RESULTS: This analysis confirmed the results of the exploratory study with the same best model and slightly better statistical significance. There was a significant inverse association between a history of suicide attempts and the ratio of mean winter insolation to mean summer insolation (mean winter insolation/mean summer insolation). This ratio is largest near the equator which has little change in solar insolation over the year, and smallest near the poles where the winter insolation is very small compared to the summer insolation. Other variables in the model associated with an increased risk of suicide attempts were a history of alcohol or substance abuse, female gender, and younger birth cohort. The winter/summer insolation ratio was also replaced with the ratio of minimum mean monthly insolation to the maximum mean monthly insolation to accommodate insolation patterns in the tropics, and nearly identical results were found. All estimated coefficients were significant at p < 0.01.

CONCLUSION: A large change in solar insolation, both between winter and summer and between the minimum and maximum monthly values, may increase the risk of suicide attempts in bipolar I disorder. With frequent circadian rhythm dysfunction and suicidal behavior in bipolar disorder, greater understanding of the optimal roles of daylight and electric lighting in circadian entrainment is needed.

Language: en

Keywords

Psychiatry; Suicide; Bipolar disorder; Circadian; Seasonal variation; Solar insolation; Sunlight