Table 3. . Numbers and enriched function of epigenome-wide association studies associated with psychological stress across the life span.

Time of stress	Stress type	Age at sampling	Number of studies†	Number of studies‡	Functional pathway§
Prenatal development	Maternal depression/anxiety	Infant	10	5	Brain development (1); transcription regulation (1)
	Low SES		3	3	Transcription regulation (2); stress response (2); immunity (1); brain development (1); metabolism (1); cancer (1)
	Other psychological stress		8	7	Brain development (1); metabolism (1); transcription regulation (1); stress response (1); psychiatric disorder (1)
Postnatal development	Child maltreatment	Child/adolescent	5	4	Stress response (3); physical/psychiatric disorder (3); brain development (1)
		Adult	11	7	Brain development (4); transcription regulation (4); cellular signaling (3); stress response (2); immunity (2); metabolism (2)
	Low SES	Child/adolescent	3	3	Immunity (2); cellular signaling (2); tissue growth (1); metabolism (1)
		Adult	7	5	Immunity (3); cellular signaling (2); metabolism (1); brain development (1); growth development (1)
	Other psychological stress	Child/adolescent	8	6	Immunity (3); brain development (2); cellular signaling (2); stress response (2); metabolism (2)
		Adult	4	3	Brain development (1); cellular signaling (1); immunity (1)
Adulthood	Work-related stress	Adult	4	2	Cancer-related pathways (2); immunity (1)
	Low SES		4	1	Immunity (1); stress response (1)

^†Original EWAS included in PRISMA selection.

^‡Subset of EWAS with statistical power >75%.

^§Numbers in brackets refer to the repeated number of DMGs enriched in the pathways. Biological pathways of immunity were repeated across three lifespan periods.

DMGs: Differential methylation genes; EWAS: Epigenome-wide association studies; SES: Socioeconomic status; PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-Analyses.