The more sativa that a plant has in it the more of a head trip you will get from smoking it. Sativa plants are not good for people who have anxiety because if you smoke a lot you will be tripping in your head, your pulse rate will go up and your thoughts will be all over the place. This can lead to a panic attack or just simply feeling nervous or anxious. Indicas or hybrids that are mostly indica are better for people with anxiety because they slow your thoughts down and calm you, rather than speed you up and make you think faster.