A parent must become aware of some of the signals a child may be showing if on drugs, the National Youth Network says. Sudden personality changes or poor schoolwork, unusual temper tantrums, withdrawal from family activities and deterioration in appearance are a few signs. It's difficult for a parent to accept the belief that a child is on drugs. It can cause overwhelming feelings of guilt, along with constant worry about the child. Parents who communicate well with their children often help them stay away from drugs. But communication is even more important when a teen is doing drugs. Forgiveness, compassion and openness are important in getting help for the child from a professional or support group. When a family is broken apart by drugs, it can become stronger by helping a troubled teen through the crisis.