van Velzen LS, Colic L, Ceja Z, Dauvermann MR, Villa LM, Savage HS, Toenders YJ, Dehestani N, Zhu AH, Campos AI, Salminen LE, Agartz I, Alexander N, Ayesa-Arriola R, Ballard ED, Banaj N, Barkhau C, Başgöze Z, Bauer J, Benedetti F, Berger K, Besteher B, Brosch K, Canal-Rivero M, Cervenka S, Colle R, Connolly CG, Corruble E, Courtet P, Couvy-Duchesne B, Crespo-Facorro B, Cullen KR, Dannlowski U, Deverdun J, Diaz-Zuluaga AM, Dietze LMF, Evans JW, Fani N, Flinkenflügel K, Friedman NP, Gotlib IH, Groenewold NA, Grotegerd D, Hajek T, Hatoum AS, Hermesdorf M, Hickie IB, Hirano Y, Ho TC, Ikemizu Y, Iorfino F, Ipser JC, Isobe Y, Jackowski AP, Jollant F, Kircher T, Klug M, Koopowitz SM, Kraus A, Krug A, Le Bars E, Leehr EJ, Li M, Lippard ETC, Lopez-Jaramillo C, Maximov II, McIntosh AM, McLaughlin KA, McWhinney SR, Meinert S, Melloni E, Mitchell PB, Mwangi B, Nenadić I, Nerland S, Olie E, Ortiz-García de la Foz V, Pan PM, Pereira F, Piras F, Piras F, Poletti S, Reineberg AE, Roberts G, Romero-García R, Sacchet MD, Salum GA, Sandu AL, Sellgren CM, Shimizu E, Smolker HR, Soares JC, Spalletta G, Douglas Steele J, Stein F, Stein DJ, Straube B, Teutenberg L, Thomas-Odenthal F, Usemann P, Valabregue R, Valencia-Echeverry J, Wagner G, Waiter G, Walter M, Whalley HC, Wu MJ, Yang TT, Zarate CA, Zugman A, Zunta-Soares GB, van Heeringen K, van Rooij SJH, van der Wee N, van der Werff S, Thompson PM, Blumberg HP, van Harmelen AL, Rentería ME, Jahanshad N, and Schmaal L
Previous studies have suggested that alterations in white matter (WM) microstructure are implicated in suicidal thoughts and behaviours (STBs). However, findings of diffusion tensor imaging (DTI) studies have been inconsistent. In this large-scale mega-analysis conducted by the ENIGMA Suicidal Thoughts and Behaviours (ENIGMA-STB) consortium, we examined WM alterations associated with STBs. Data processing was standardised across sites, and resulting WM microstructure measures (fractional anisotropy, axial diffusivity, mean diffusivity and radial diffusivity) for 25 WM tracts were pooled across 40 cohorts. We compared these measures among individuals with a psychiatric diagnosis and lifetime history of suicide attempt ( n =652; mean age=35.4±14.7; female=71.8%), individuals with a psychiatric diagnosis but no STB (i.e., clinical controls; n =1871; mean age=34±14.8; female=59.8%), and individuals with no mental disorder diagnosis and no STB (i.e., healthy controls; n =642; mean age=29.6±13.1; female=62.9%). We also compared these measures among individuals with recent suicidal ideation ( n =714; mean age=36.3±15.3; female=66.1%), clinical controls ( n =1184; mean age=36.8±15.6; female=63.1%), and healthy controls ( n =1240; mean age= 31.6±15.5; female=61.0%). We found subtle but statistically significant effects, such as lower fractional anisotropy associated with a history of suicide attempt, over and above the effect of psychiatric diagnoses. These effects were strongest in the corona radiata, thalamic radiation, fornix/stria terminalis, corpus callosum and superior longitudinal fasciculus. Effect sizes were small (Cohen's d < 0.25). Recent suicidal ideation was not associated with alterations in WM microstructure. This large-scale coordinated mega-analysis revealed subtle regional and global alterations in WM microstructure in individuals with a history of suicide attempt. Longitudinal studies are needed to confirm whether these alterations are a risk factor for suicidal behaviour., Competing Interests: Conflicts of interest ALvH receives consultancy fees from the Augeo foundation. CAZ is a full-time US government employee. He is listed as a co-inventor on a patent for the use of ketamine and its metabolites in major depression and suicidal ideation. Dr. Zarate has assigned his patent rights to the U.S. government but will share a percentage of any royalties that may be received by the government. HPB has consulted to the Milken Institute. MW is a member of the following advisory boards and gave presentations to the following companies: Bayer AG, Germany; Boehringer Ingelheim, Germany; and Biologische Heilmittel Heel GmbH, Germany. MW has further conducted studies with institutional research support from HEEL and Janssen Pharmaceutical Research for a clinical trial (IIT) on ketamine in patients with MDD, unrelated to this investigation. MW did not receive any financial compensation from the companies mentioned above. IA received speakers honorarium from Lundbeck. IBH is the Co-Director, Health and Policy at the Brain and Mind Centre (BMC) University of Sydney. The BMC operates an early-intervention youth services at Camperdown under contract to headspace. He is the Chief Scientific Advisor to, and a 3.2% equity shareholder in, InnoWell Pty Ltd which aims to transform mental health services through the use of innovative technologies. AC reports being currently an employee of the Regeneron Genetics Center, and may own Regeneron stock or stock options. JCS acknowledge to be related with the next companies ALKERMES (Advisory Board), BOEHRINGER Ingelheim (Consultant), COMPASS Pathways (Research Grant), JOHNSON & JOHNSON (Consultant), LIVANOVA (Consultant), RELMADA (Research Grant), SUNOVION (Research Grant),Mind Med (Research Grant). PMP received payment or honoraria for lectures and presentations in educational events for Sandoz, Daiichi Sankyo, Eurofarma, Abbot, Libbs, Instituto Israelita de Pesquisa e Ensino Albert Einstein, Instituto D’Or de Pesquisa e Ensino. All other authors report no biomedical financial interests, disclosures or potential conflicts of interest.