I find that its the hybrids that cause anxiety for me. My theory is that its kind of a conflict of interests going on. The sativa side makes me want to go out and do something while the indica side is trying to keep the remote in my hands. Pure Sativa's always put a big smile on my face and the last thing on my mind is anxiety. Indica's are more prone to giving me anxiety because I don't like it when my body feels to far gone from control. I guess it depends who you are.