Prozac is helping me with that issue currently. I take Symbyax which is Zyprexa and Prozac combined. Unmedicated I get really bad intrusive thoughts of the anxious variety (usually). That was still happening when I was just on Zyprexa, and then I switched to Symbyax and it has gotten noticeably better.

My pdoc would disagree with you on it not possibly being OCD just because there are no compulsive behaviors such as hand washing. She thinks my intrusive thoughts problem is OCD related, which is part of why she leaned towards trying Prozac. I wish I had the type of OCD where I was cleaning all the time and such, at least I'd feel somewhat useful lol. But instead it's stuff like always suddenly thinking I am going to fall down the stairs and then tensing up and gripping the rail the whole way down.

IME the downside with Prozac is that it takes a while to feel it working. Whereas I felt different within a couple days on Zyprexa, it took over a week before I started noticing improvement after the addition of Prozac. I've been on it a month now, though, and don't worry about stupid stuff nearly as much.