I think Doc may have Asperger Syndrome. He can be absent-minded at times, which is often a symptom of Asperger Syndrome. He often focuses on only one thing, science, particularly time travel. He has very few friends and is highly intelligent. Apparently, he likes things done routinely, such as Einstein being fed at 8AM everyday.

I just responded on the IMDB boards, but I'll post here, too.

I don't know too much about Asperger Syndrome, to be honest! Other people have suggested that about Doc, though. He doesn't seem to be a very sociable kind of person - even though I would like to think that most of Hill Valley doesn't think ill of Doc. Having become very much intrigued with the history of Hill Valley - I would hate to think that the majority of the population would be so judgemental.

He does seem to focus almost entirely on science. One fanfic writer, Aaron Jenkins, seems to have suggested that Doc's relationship with Clara might not be such a happy one - and that Clara may even feel like she is always having to compete with science (time travel, in particular). Even though she's very fond of Jules Verne and astronomy, she's obviously not as much into science as Doc is.

Anyway, this is a very interesting subject.

The term was first coined in a college paper in 1981, but it still wasn't heard of until the early 90s.

I have heard this theory before. Personally I don't think Bob Gale and Bob Zemeckis meant for Doc to have Asperger Syndrome, but that the way he acts is just because he is made out to be the typical "mad scientist" type. This topic also reminds me of the theory that Marty is diabetic because he orders a Pepsi Free! :D

I don't think he's diabetic. I just think he's a bit of a health nut.

Actually, Marty doesn't really strike me as being a health food nut. Elyse Keaton from Family Ties is a bit of a health food nut, though. I may disagree with Alex P Keaton on politics - but, when it comes to food, I find myself agreeing with him. I think it's just when it comes to soft drinks, Marty is not as keen on regular soft drinks. He does have all this candy behide his bed, though.

I don't think Marty was a health nut either. The "real" reason Marty drinks Pepsi Free is because the writers wanted to have the joke of Marty ordering a Pepsi Free in 1955. There is no explanation given in the movie why Marty would drink Pepsi Free which is mostly likely because there is no reason, the writers just liked the Pepsi Free gag. However I find the speculation about why Marty would drink Pepsi Free interesting. Even though I don't think that Marty is a diabetic or a health nut, these are interesting ideas.