https://www.sciencedirect.com/science/article/pii/S0889159119310773 From a press release by the university: https://www.vai.org/pregnancy-related-depression-lena-brundin/ Hello tryptophan my old friend. I frankly find it doubtful that cognition, thoughts and beliefs, play more than a minor role, if at all, in the vast majority of depression. If it does it's probably trivial. Far too many happy people with everything going on for them developed it. Meanwhile this pathological thinking has probably discouraged many potential avenues because of a certainty over a critical role of psychology, especially thoughts and behaviors. That hypothesis makes little sense and frankly looking at the BPS obsession over those and how convinced they are they play a role only reinforces that. Their beliefs almost seem like a standard bearer that the opposite is more likely to be true. And beyond that very likely that nearly all, if not absolutely all, of the maligned chronic diseases have similar causes, in the immune system though involving different mechanisms in response to pathogens, toxins, pollution or repeated infections. I really hope that this here leads to better handling of PPD, especially shedding off the misguided beliefs that formed all earlier thinking.