To me, there is no difference between schizophrenia and bipolar, other than stigma. People would vastly prefer to publicly announce themselves bipolar, Patty Duke and Carrie Fisher being proof of this. There are vastly far fewer people willing to come out and say they are "schizophrenic". There is a pecking order here. People labelled "schizophrenic" find themselves at the bottom.
The distinctions are artificial from the point of view of treatment. There are no diagnostic tests, no genes have been found, people with these labels get the same meds,and they may find that this year's label of bipolar is next year's schizophrenia, or vice versa. Their diagnosis may even morph into depression.
I say that symptoms are on a continuum and it depends where on the continuum you were last found to earn you the current label.
If you are getting the same meds as the next guy, this should make you very suspicious of these labels and these meds in the first place.
I was heartened when Chris, for a brief flowering moment (his "Prague spring"), was becoming bipolar. This to me showed progress, from being totally incapacitated by existential angst to becoming in your face, annoying, hard to handle, bipolar. It showed a level of emotionalism that he previously hadn't demonstrated. He was becoming more real. He was the same person, though. Had he been taken to the hospital for the first time without his previous psychiatric label, he most likely would be deemed "bipolar".
When you start racking up one or more labels, it's high time to question the science that is supposedly underpinning it all. Think about it. It is extremely cynical of the pharmaceutical companies and completely stupid for the medical profession to pretend there are these distinctions when, in fact, they are handing out the same pills.