Table 1.

Effect modification and interaction of timing of exposure

Authors	Exposure	Outcome	EM/INT	Result
Friedman et al. (1984)	Parental psychiatric disorder (primarily MDD and alcohol)	SA	EM: Exposed before and after 14 years	50% of offspring with SA had mothers with a chronic psychiatric illness before age 14 years v. 5% of offspring without SA (Fishers exact test p < 0.01)
Niederkrotenthaler et al. (2012)	Parental psychiatric inpatient care	SRB/suicide	EM: Exposure age categories: <3 years, 3–10 years, >10 years	Predicting offspring SRB (p-trend < 0.001) <3 years (OR 2.6, 95% CI 2.5–2.8) 3–10 years (OR 2.3, 95% CI 2.2–2.5) >10 years (OR 2.2, 95% CI 2.0–2.3) Predicting offspring suicide (p-trend = 0.027) <3 years (OR 2.5, 95% CI 2.0–3.1) 3–10 years (OR 1.9, 95% CI 1.5–2.4) >10 years (OR 2.1, 95% CI 1.8–2.6)
Rossow & Moan (2012)	Parent alcohol	SRT/SA	Interaction: offspring age × parental intoxication EM: Jr. High v. high-school	Significant interaction for offspring SRT (p < 0.05) Non-significant interaction for offspring SA (NR) Offspring SRT: Jr. High (OR 6.3, 95% CI 3.9–10.1) High-school (OR 2.6, 95% CI 1.4–4.8)

Alcohol, alcohol use/dependence; CI, confidence interval; EM, effect modifier; HR, hazard ratio; INT, interaction; MDD, major depressive disorder; NR, not reported; OR, odds ratio; psych: SA, suicide attempt; SRB, suicide-related behaviour; SRT, suicide-related thoughts.