They can be co-morbid, but the traits most frequently associated with Asperger's that can often be misinterpreted as OCD, are seeming obsession with special interests and the need for ritual routines. The two are both very different from OCD rituals though. OCD rituals are usually to compensate for something. One man I read from on a different forum said he touches things in the room three times each, and the purpose is to prevent the death of his children. He know intellectually it doesn't make any sense, but he is still driven to do it, and becomes extremely anxious if he doesn't.
The routine rituals that apply to Aspies are quite a bit different. Some Aspie kids, for example might get extremely anxious if they aren't read a bedtime story every night, or if the bedtime ritual of "brush teeth, put on pajamas, read story, then turn out the light," (or similar routines ~ I realize many refuse to brush teeth) is disrupted for any reason. Unexpected trips to the store, or visits that disrupt normal routines can cause the same problem. This is why advanced warning and mental preparation is so important.
The part about confusing special interest obsessions is just a misunderstanding of what OCD type obsessions are really about. OCD obsessions and rituals are even more irrational. Even the people with OCD seem to know they are. Aspies may not even understand why they are getting anxious, and all it is is a normal routine that's being disrupted.
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I'm not likely to be around much longer. As before when I first signed up here years ago, I'm finding that after a long hiatus, and after only a few days back on here, I'm spending way too much time here again already. So I'm requesting my account be locked, banned or whatever. It's just time. Until then, well, I dunno...