Severity of depression on the BDI was significantly correlated with the novelty vertex source (r = − .30, n = 94, p = .003) as well as the late response-related source (r = − .28, n = 94, p = .006). However, the association was presumably due to the patient/control classification, as it was not supported when controls were excluded. In contrast, the Chapman measure of physical anhedonia (Chapman & Chapman, 1978) was significantly correlated with the response-related source (542), both across all participants (r = − .25, n = 89, p = .02) and for patients alone (r = − .32, n = 43, p = .04).
