yep
if you can focus on things while answering questions, you can pass one. My buddy just passed one for the fire department. He also took 5mg of valium before he went in. The first ? they asked was if he took anything to alter his mood before the polygraph. Also, they asked him about smoking pot, cigarettes, doing/selling drugs... all of these which he did do in the past, and he passed them. But, he failed a ? about stealing from an employer, which he never did do. So IMO, polygraphs suck ass.