Table 3.

Potential risk factors of depression in patients with CH-C.

Social factors	Sociodemographic factors	Clinical factors	Genetic factors (Polymorphisms)
Cultural differences Stigmatization Long time stress	Age Female Ethnicity	A previous history of depression Fatigue Sleep disturbance	5-HTTLPR (the s allele of the short/long polymorphism) 5-HTR1A (C-1019G) IDO (rs9657182) IFNAR1 Immune genes (IL-6, TNF-α) Others (PLA2, COX2, epsilon4)

5-HTTLPR, the serotonin transporter gene-linked polymorphic region; 5-HTR1A, the serotonin 1A receptor; IDO, indoleamine-2,3-dioxygenase; PLA2, Phospholipase A2; COX2, cyclooxygenase 2.