Table 1.

Descriptive characteristics of studies of the association between GRIK4 and antidepressant response in depressed patients.

Author (year)	Cases† (n)	Ancestry	Mean age of control group	Gender ratio‡	Response	Antidepressant treatment	Ref.
Paddock et al. (2007)	1094	European	40.8	1.61	50% reduction in base QIDS score	SSRI	[9]
Perlis et al. (2010)	296	European	44.2	1.72	50% reduction in base HAM-D score	SNRI	[10]
Horstmann et al. (2010)	300	European	49.5	1.35	50% reduction in base HAM-D score	Naturalistic§	[12]
Serretti et al. (2012)	200	European	50.1	2.70	HAM-D score <17 after 4 weeks of treatment	Naturalistic§	[11]
Pu et al. (2013)	279	Asian	38.2	1.42	50% reduction in base HAM-D score	SSRI or SNRI	[13]

^†For which GRIK4 was genotyped.

^‡Gender ratio = females cases:male cases.

^§Individual treatment determined by doctors. All classes of antidepressants were allowed.

HAM-D: Hamilton Rating Scale for Depression; QIDS: Quick Inventory of Depressive Symptomology; SNRI: Serotonin–norepinephrine reuptake inhibitor; SSRI: Selective serotonin reuptake inhibitor.