Either/or. That's what I strongly believe.

Things very different in nature are often/always the same in appearance. That's pretty much the basis of all that I believe. Life's not paradoxical by chance but by necessity.

So yes, the appearance of a lack of empathy, maybe a lack of sympathy or a delusion based on empathy, is very much a possibility when having BP/SZ. SZ is of course the very best example. SZ and ASD are very different in nature. BP and ASD too. But ASD symptoms overlap with those of SZ and BP.

What makes it difficult is that the nature of things is sometimes considered unimportant in diagnosis. It's all appearances. But there are a number of criteria for symptoms which reflect the nature of BP (or SZ) more "faithfully". For BP that is an episodic nature.

But in practice, good psychiatrists will look for the nature of the problem in various ways which go beyond following a cookbook (as the DSM-IV mentions it is not).

So episodic nature (of delusions) is important. But I'd say it's intensity, as far as appearance goes. But true intensity. The good thing is that many with ASD try to fake it and those with SZ don't bother and it's genuine, only barely noticeable.

Not depression. ASD may cause depression. But not bipolar depression.

All other problems may be something about your personality or an anxiety disorder.

There are also psychological tests (not questionnaires) for measuring the difference. There are also blood tests, one in particular seems to actually be rather reliable but I forgot the name. But I wouldn't try any of that.

A psychiatrist that uses her intuition is required. But most are not very good at that, so they should see you change over a long period of time.

If you admit you were a complete idiot believing what you believed maybe a day ago then it's likely not ASD.