On the basis of summary fit statistics along with residuals for the mean and covariance structures, a quadratic model with zero variance and covariances for the quadratic growth factor was deemed acceptable for both sexes. Males: CFI = 0.973, TLI = 0.964, RMSEA = 0.045, females: CFI = 0.965, TLI = 0.953, RMSEA = 0.060. More details on model fit can be found in Supplementary Table X2. Figure 2 shows estimated trajectory for depressive symptoms complete with its 95 % confidence interval for this model. Since each indicator would be expected to exhibit its own trajectory, we illustrate with the first indicator only. Under assumption of parameter invariance all three indicators display parallel trajectories through time, from different levels at baseline.
