BDNF and schizophrenia: Intrinsic curvature has previously been used and shown to be sensitive to cortical differences related to connectivity in patients affected by schizophrenia compared to healthy controls (Ronan et al., 2012) and in a study of healthy participants with various combinations of the brain derived neurotrophic factor (BDNF) val66met polymorphism (Forde et al., 2014).