Rainbow, this is what pdoc's do for a living. He'll ask you some pretty pointed questions about your symptoms: obsessive thinking, depression, anxiety, etc. and make his decisions based on your symptoms. He'll probably start with something pretty standard and at a low dose, wanting to see you again in a few weeks after the med has a chance to kick in (which can take some time). Pdoc's know what meds to use for what symptoms and will start with what they've found most effective in similar cases in the past; then they'll work from there. Remember, you aren't his first rodeo.