Citation

Bauer M, Glenn T, Alda M, Andreassen OA, Angelopoulos E, Ardau R, Ayhan Y, Baethge C, Bauer R, Baune BT, Becerra-Palars C, Bellivier F, Belmaker RH, Berk M, Bersudsky Y, Bicakci Ş, Birabwa-Oketcho H, Bjella TD, Cabrera J, Wo Cheung EY, Del Zompo M, Dodd S, Donix M, Etain B, Fagiolini A, Fountoulakis KN, Frye MA, Gonzalez-Pinto A, Gottlieb JF, Grof P, Harima H, Henry C, Isometsä ET, Janno S, Kapczinski F, Kardell M, Khaldi S, Kliwicki S, König B, Kot TL, Krogh R, Kunz M, Lafer B, Landén M, Larsen ER, Lewitzka U, Licht RW, Lopez-Jaramillo C, MacQueen G, Manchia M, Marsh W, Martinez-Cengotitabengoa M, Melle I, Meza-Urzúa F, Ming MY, Monteith S, Morken G, Mosca E, Mozzhegorov AA, Munoz R, Mythri SV, Nacef F, Nadella RK, Nery FG, Nielsen RE, O'Donovan C, Omrani A, Osher Y, Sørensen HØ, Ouali U, Ruiz YP, Pilhatsch M, Pinna M, da Ponte FDR, Quiroz D, Ramesar R, Rasgon N, Reddy MS, Reif A, Ritter P, Rybakowski JK, Sagduyu K, Raghuraman BS, Scippa ÂM, Severus E, Simhandl C, Stackhouse PW, Stein DJ, Strejilevich S, Subramaniam M, Sulaiman AH, Suominen K, Tagata H, Tatebayashi Y, Tondo L, Torrent C, Vaaler AE, Vares E, Veeh J, Vieta E, Viswanath B, Yoldi-Negrete M, Zetin M, Zgueb Y, Whybrow PC. J. Psychiatr. Res. 2019; 113: 1-9.

Affiliation

Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, University of California Los Angeles (UCLA), Los Angeles, CA, USA.

Copyright

(Copyright © 2019, Elsevier Publishing)

DOI

10.1016/j.jpsychires.2019.03.001

PMID

30878786

Abstract

In many international studies, rates of completed suicide and suicide attempts have a seasonal pattern that peaks in spring or summer. This exploratory study investigated the association between solar insolation and a history of suicide attempt in patients with bipolar I disorder. Solar insolation is the amount of electromagnetic energy from the Sun striking a surface area on Earth. Data were collected previously from 5536 patients with bipolar I disorder at 50 collection sites in 32 countries at a wide range of latitudes in both hemispheres. Suicide related data were available for 3365 patients from 310 onset locations in 51 countries. 1047 (31.1%) had a history of suicide attempt. There was a significant inverse association between a history of suicide attempt and the ratio of mean winter solar insolation/mean summer solar insolation. This ratio is smallest near the poles where the winter insolation is very small compared to the summer insolation. This ratio is largest near the equator where there is relatively little variation in the insolation over the year. Other variables in the model that were positively associated with suicide attempt were being female, a history of alcohol or substance abuse, and being in a younger birth cohort. Living in a country with a state-sponsored religion decreased the association. (All estimated coefficients p < 0.01). In summary, living in locations with large changes in solar insolation between winter and summer may be associated with increased suicide attempts in patients with bipolar disorder. Further investigation of the impacts of solar insolation on the course of bipolar disorder is needed.

Copyright © 2019 Elsevier Ltd. All rights reserved.

Language: en

Keywords

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