Hi doctor, when I was in my 10th grade I don't know how and why my mind began to crave for chalks to eat. It happened suddenly and now it has became my habit ,i can eat 1 chalk a day and cannot resist myself when I see them. Not only this in absence of chalks I began to eat cement. Please doctor help me, I don't want to eat them but when I see them I cannot resist them. Also if they are not present in front of me my mind began to think ways to get any one of them and when I didn't get I began to feel restless, depressed and cannot concentrate on anything. I realy need your help? Please help me? P.S:- I wasn't having any habit of eating anything like this in my childhood? It suddenly started.