Fig. 5.

Relationship between amygdala connectivity and age across samples. Given that age is a key between-group difference variable across the 4 examined samples, we conducted a follow-up validity check analysis to ensure that age is not significantly related to any of the main between-group effects. Here, we show the relationship between age across all participants and amygdala-orbitofrontal cortex (OFC) (a) and amygdala-brainstem connectivity (b). There was no significant relationship between age and reported connectivity effects for the OFC region (OFC: r = .07, P = .37, n.s., nonsignificant). However, across all subjects (N = 165), there was a modest, but significant relationship between amygdala-brainstem connectivity and age (brainstem: r = −.19, P < .02, 2 tailed). Nonetheless, as evident from the plot, the HR group (yellow) was shifted to the right (increased connectivity) relative to all other groups (lower right quadrant of plot b), suggesting specifically elevated amygdala-brainstem connectivity. Moreover, age, when used as a covariate, did not alter the between-group ANOVA F-test. Nonetheless, we conducted an additional age-matched follow-up analysis to ensure that brain maturity was not a confounding variable for the brainstem effect (see figure 6). Groups: C-SCZ, chronic schizophrenia; EC-SCZ, early-course schizophrenia; HCS, healthy comparison subjects; HR, high risk.