Psychology thesis ideas?

So I need a topic/thesis statement for my senior thesis. It needs to be broad enough ( 40 pages ) but still be narrow enough that I can defend it; I also don't want to bite off more than I can chew. I want to do it on something related to psychology. I don't have many ideas. I am pretty much interested in many branches which presents a problem cause I can't decide. But I am more interested in clinical, counseling, and abnormal psychology. Sooo any ideas? Doesn't have to fit those categorys. thanks :)