Opiate addiction is recognized as a central nervous system disorder, caused by continuous opiate intake. After prolonged opiate use, the nerve cells in the brain, which would otherwise produce endogenous opiates (natural painkillers, or endorphins), cease to function normally. The body stops producing endorphins because it is receiving opiates instead. The degeneration of these nerve cells causes a physical dependency to an external supply of opiates. Abrupt or sudden abstinence from opiates induces yet another traumatic disorder - withdrawal syndrome.