Table 1.

Overview of studies providing evidence on changes in DNA methylation associated with risk SNPs for common psychiatric disorders.

Type of association between risk SNP and DNA methylation	Phenotype	Tissue	Developmental stage	Size	DNA methylation quantification method	Study describing the association
mQTL	Schizophrenia	Dorsolateral prefrontal cortex	Adult	N = 216	27K methylation array	(87)
		Fetal brain	Prenatal	N = 166	450K methylation array	(88)
		Blood	Adult	N = 639	450K methylation array	(49)
		Prefrontal cortex, blood, saliva	Adolescent, adult	N = 1,292	EPIC methylation array, 450K methylation array	(89)
	Bipolar disorder	Cerebellum	Adult	N = 153	27K methylation array	(90)
		Blood	Adult	N = 725	iPLEX	(92)
	Major depression	Blood	Adult	N = 3,284	450K methylation array	(16)
		Blood	Adult	N = 742	450K methylation array	(93)
	Autism	Blood	Child	N = 968	450K methylation array	(97)
		Blood	Neonatal, child	N = 1,257	450K methylation array	(65)
	Autism, attention-deficit/hyperactivity disorder, autism	Fetal brain, brain cortical tissue, blood	Prenatal, adult	N = 2,353	450K methylation array, EPIC methylation array	(94)
	Attention-deficit/hyperactivity disorder	Saliva	Child	N = 611	EPIC methylation array	(98)
	Schizophrenia, bipolar disorder, major depression, autism, attention-deficit/hyperactivity disorder	Fetal brain, brain cortical tissue	Prenatal, adult	N = 1,178	450K methylation array	(96)
	Alcohol dependence disorder	Prefrontal cortex	Adult	N = 48	450K methylation array	(95)
CpG-SNP	Major depression	Blood	Adult	N = 1,132	MBD-seq	(99)
	Schizophrenia	Blood, Broadman area 10	Adult	N = 1,474	MBD-seq	(100)
	Alcohol dependence disorder	Dorsolateral prefrontal cortex	Adult	N = 28	Pyrosequencing	(101)

mQTL, methylation Quantitative Trait Locus; SNP, single-nucleotide polymorphism.