I am concerned with my 10 year old son. He chews on everything, sometimes even eating it. Clothing, plastic, his fingers and fingernails, paper, erasers, pens & pencils. If he picks it up it will at some point go into his mouth. He has been tested for ADD & ADHD both were negative he also has been tested for food and environmental allergies along with Celiacs all have come back negative. We are also have hygiene issues, lying, aggression and he is very reactionary. Any suggestions? His school is less than helpful along with the therapist we are seeing says he is "stumped". Please help