“…PSD leads to a diminished quality of life, delayed recovery of neurological function, increased mortality, and a greater burden on families and society (Hackett et al, 2010). In recent years, much attention has been paid to the serotonin (5-hydroxytryptamine; 5-HT) transporter gene-linked polymorphic region (5-HTTLPR) genotype in PSD patients and the neurotransmitter serotonin hypothesis, but current studies show that the correlation between 5-HTTLPR and PSD is controversial (Fang and Cheng, 2009;Choi-Kwon et al, 2012;Mak et al, 2013). The present study further explores the association between the 5-HTTLPR and PSD from a biological viewpoint in order to provide a theoretical basis for the etiology of PSD.…”