Table 3. Mediation of Gene by Intervention Interaction (GxI) Effects on Age-25 Externalizing Psychopathology by GxI Effects on Proximal Developmental Phenotypes.

Models tested mediated moderation. Direct effects refer to the GxI effects on age-25 externalizing psychopathology that was independent of any GxI effect on the proximal developmental phenotype. Indirect effects refer to GxI effects on age-25 externalizing psychopathology that were mediated by the proximal developmental phenotypes.

Model		Effect Estimate		[95% CI]	Mediation Ratio
(1)	Mediator: Child Externalizing Psychopathology
	Direct Effect	−1.44	*	[−2.36,−0.63]	---
	Indirect Effect	−0.27	*	[−0.64,−0.05]	0.16
(2)	Mediator: Adolescent Problem Behavior
	Direct Effect	−0.87		[−1.87,0.10]	---
	Indirect Effect	−0.84	*	[−1.52,−0.38]	0.49
(3)	Mediator: Child Externalizing Psychopathology & Adolescent Problem Behavior
	Direct Effect	−0.75		[−1.73,0.24]	---
	Indirect Effect 1: GxI-->Child Ext.-->Age25 Ext.	−0.16		[−0.46,0.02]	0.09
	Indirect Effect 2: GxI-->Child Ext.-->Adolescent Problems-->Age25 Ext.	−0.11	*	[−0.34,−0.02]	0.07
	Indirect Effect 3: GxI-->Adolescent Problems-->Age25 Ext.	−0.69	*	[−1.39,−0.28]	0.40
	Total Indirect Effects	−0.96	*	[−1.70,−0.56]	0.56

For ease of interpretation, effect estimates that are statistically significant are denoted with a *. Models 1 and 2 tested mediated moderation for the two developmental phenotypes in turn. Model 3 tested mediated moderation when both developmental phenotypes were included simultaneously. In Model 3, indirect effect 3 can be interpreted as portion of the GxI effect on age-25 externalizing psychopathology that is attributable to GxI effects on adolescent problem behavior only (i.e. not accounted for by GxI effects on child externalizing psychopathology).