I wonder sometimes if there are more than a few conditions with similar symptoms all tagged bipolar or schizophrenia. There are symptoms observed by the treating doctor, which can be qualified by an interview with the patient who is generally not in a state to give an objective description. Often the questions can be suggestive, and the answers can depend on whether the patient is prepared to co-operate, or be contrary. This study does point to an imbalance that can occur as a matter of course, and may show that many cases of bipolar disorder or schizophrenia, are not necessarily unusual, hereditary or chronic but can strike due to something as simple as an unbalanced diet, sleep deprivation, or a hormone deficiency. An unbalanced lifestyle can throw our minds off balance. It's all part of the same unit. Mind Body and soul

My own basic research suggests that the chemical aspects of serious and psychotic illness is common, and too that the emergence of illness is overdetermined, that is due to many causes including those you mention and social, evne existential, factos in some, not all, cases, each profile different for each individual. And too that the very old system of classifications is wrong and clumsy, and that conceptual confusion needs addressing, and a completely fresh way of looking at things.