“…It is positively related to mood disorder severity, cognitive dysfunctions, levels of hopelessness, increased risk of substance abuse, aggressive and impulsive behaviours, emotional dysregulation and increased risk of suicidality (Baglioni, Spiegelhalder, Lombardo, & Riemann, 2010;Ritter et al, 2011;Boudebesse & Henry, 2012;Ritter et al, 2012;Conroy & Arnedt, 2014;Kamphuis, Dijk, Spreen, & Lancel, 2014;Schaffer et al, 2015;Kanady, Soehner, Klein, & Harvey, 2017;Ng et al, 2015;Woosley, Lichstein, Taylor, Riedel, & Bush, 2014;Woznica, Carney, Kuo, & Moss, 2015). Insomnia plays an important role in relapses and recurrences of mood disorders, it is an independent risk factor for mood disorders, and a frequent early sign occurring prior to both depressive and manic episodes (Baglioni et al, 2011;Ellis, Perlis, Gardani, Bastien, & Espie, 2014;Gruber et al, 2011;Kanady, Soehnera, & Harvey, 2015;Pigeon, Bishop, & Krueger, 2017;Ritter et al, 2015;Rumble et al, 2015;Sakurai, Suzuki, Yoshimura, Mimura, & Uchida, 2017). Recently, it has been shown that targeting insomnia may improve not only insomnia symptoms but favourably impacts on the trajectory of mood disorders (Franzen & Buysse, 2008;Geoffroy et al, 2017;Jansson-Fröjmark & Norell-Clarke, 2016;Manber et al, 2011) and, by reducing depressive symptoms, it may even prevent major depressive forms (Christensen et al, 2016).…”