“…This disturbance may become chronic and persist for months or even years after cancer treatment is completed. In addition, sleep disturbances are also caused by physical illness or pain, psychological disorders, medication, depression, fatigue, and anxiety, hence, it is widely concerned as the second most difficult disorder to treat (Fiorentino, 2011;Arslan & Fadıloğlu, 2009;Stone & Minton, 2008). The sleep system is integrated with several aspects of human physiology, such as cell metabolism, cardiovascular function, cognitive function, and immune function (Dierickx et al, 2018).…”