Fig. 1
Conceptual serial mediation model where c represents the total effect (direct and indirect through mediators) between the predictor (autism) and the outcome variable (Quality of Life). Paths a1 and a2 represent the relationship between the predictor and mediators (internalizing and externalizing). Path d21 represents the relationships between the two mediators. b1 and b2 represent the relationship between the mediators and outcome variables after controlling for the predictor. The c’ path is the direct effect between the predictor and the outcome variable without the effect of the mediator variables. The indirect effect (c - c’ = a1 b1 + a2 b2 + a1 d21b2) is indicated through a statistically significant (i.e. CIs does not include zero) difference between c and c’ [53].