I have a student who one day can be a perfect angel and then the next day a teacher's worse dream. This student takes medication for ADHD and without it he is a class disruption and very disrespectful. The days that he takes his medication it is the exact opposite. He does his work and and does not hinder others from doing theirs. I have contacted his mother, but she said she cannot do anything with him. He is a smart student but the days he does not do his assignments is beginning to affect his grades. It is also hard for me because I want to distance myself from the student due to the fact I do not know which personality I will get that day. I have talked to the principals about this student and they continue to tell me to work with the student. We have had numerous talks about his grades and behavior, but it seems as if they are not working. What should I do.