TNF and bipolar disorder: Members of the TNFSF pathway are part of cell death pathways like apoptosis/pyroptosis (32,54), and while it has been debated as to whether cell death occurs in the brains of people with schizophrenia/bipolar disorder, increased TNF can directly damage neural cells in several neuroinflammatory conditions (55, 56, 57) and could result in altered neuronal function.