I’ve seen many BPS proponents that argue that
- There are no changes on a cellular or systemic level
- If there are changes, they are continuously maintained by the CNS, i.e. downstream effects of unhelpful beliefs, a stuck stress response, a mismatch between perceived capabilities and actual capabilities, an effort preference, etc.
When I’ve asked about how the CNS can cause such changes, the answer is always a bit handwavy or something like ‘the CNS regulates the immune system, so the changes must have come from the CNS’.