Jeff,
I think my answer would lie somewhere inbetween. You are right -- you aren't an expert in this area and you are not qualified to "diagnose" someone as having a psychological disorder. Moreover, students have the right NOT to claim their disability and request special treatment -- and you shouldn't be giving it if they didn't request it. But perhaps the better response is to deal with what you SEE (what you observe) and respond as you would to anyone else engaging in that behavior. No more and no less!
Dr. Jane Jarrow
