Drug users may be surprised to learn that even though they stop using there are fundamental physiological and neurological changes made to their bodies that result in shortened life spans. Even users who have stopped using long ago may find that their health has been impaired and their lives shortened. Although different drugs have different kinds of detrimental effects on the body the National Institute of Drug Abuse has learned that once addicted a person’s brain is changed forever in significant ways. These changes might include mood swings and depression that compromise a healthy life style. Former drug users are well advised to be completely honest with their doctors about their earlier drug use so that these factors can be considered when a person’s overall health is considered.