“…Insomnia is a clinically significant feature of mood disorders, and it was listed as a diagnostic criterion for mood disorders according to the Diagnostic and Statistical Manual of Mental Disorders‐DSM, starting as early as 1980 (American Psychiatric Association, ). It is highly prevalent across the course of mood disorders, as many as 80%–100% of people during the depressive episode and 45%–55% during the bipolar inter‐episode period experience insomnia (Riemann, ; Dolsen, Asarnow, & Harvey, ; Geoffroy et al., ; Ng et al., ; Rumble, White, & Benca, ). 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, ; Ritter et al, ; Boudebesse & Henry, ; Ritter et al, ; Conroy & Arnedt, ; Kamphuis, Dijk, Spreen, & Lancel, ; Schaffer et al, ; Kanady, Soehner, Klein, & Harvey, ; Ng et al., ; Woosley, Lichstein, Taylor, Riedel, & Bush, ; Woznica, Carney, Kuo, & Moss, ).…”