TREK-1, a member of the two-pore domain potassium channel family that functions as a “background leakage potassium channel”, plays important roles in regulating neuronal excitability and maintaining the resting membrane potential; its functional abnormalities are closely associated with epilepsy, pain, depression and cerebral ischaemic neurological diseases [9, 20]. Here, KCNK2 is linked to major depressive disorder.