The powerful rush people get from using meth causes many to get hooked right from the start. When it’s used, a chemical called dopamine floods the parts of the brain that regulate feelings of pleasure. Users also feel confident and energetic.
A user can become addicted quickly and soon finds he will do anything to have the rush again. As he continues to use the drug, he builds up a tolerance. That means he needs higher doses to get the same high. The higher the dose, the higher the risks.