You bring up a very valid point! As a clinical psychologist for over 3 decades, I've seen the DSM evolve from version 3 to 5. In each iteration teams of clinicians have tried to define and define the criteria by which diagnoses are made. Unfortunately, the complexity of the human mind and subjective experiences are so complex and influenced by so many factors that the diagnostic precision sought is often not possible and arbitrary criteria are used. Another thing that has bothered me is that diagnosis and treatment prescription are often unrelated (or loosely connected), especially when it comes to determining the safest and most cost-effective ways to treat a patient. That goes for both psychopharmacological and talk therapies. Thanks for pointing out the complexities and uncertainties regarding bipolar disorder. I 's also like to hear what you have to say about borderline personality disorder diagnosis, for example!