Physical Effects. Users say meth creates a feeling of euphoria along with increased energy and reduced appetite. A psychostimulant, meth is highly addictive despite, or perhaps, because of the fact that it causes profound and long-lasting damage to the brain.Post-mortem studies link the drug to diseases of aging, including coronary atherosclerosis (hardening of the arteries) and pulmonary fibrosis (scar tissue in the lungs).sers say meth creates a feeling of euphoria along with increased energy and reduced appetite. A psychostimulant, meth is highly addictive despite, or perhaps, because of the fact that it causes profound and long-lasting damage to the brain.