CAUSES OF OPIOID ADDICTION

The general term of addiction can refer to a dependence on any number of substances. However, opioid specific addiction refers to a reliance on opioids including morphine, heroin, codeine, methadone, and oxycodone [Oxycontin (TM)]1.
Heroine is a unique opioid in that it is not a prescription drug like most other opioids. Although it is possible, it is rare to find someone who begins using heroine without ever trying a prescription opioid such as morphine or oxycodone. Most heroin addicts become so when opioids become more difficult to obtain, whether this is due to rising costs or declining access. Heroine produces the same response in the brain, but is much cheaper and easily accessible on the street. However, because it is on the streets it is not regulated; many deaths due to heroine are because it is laced with something else, or the needles used to administer it are not sanitary.
Regardless of which opioid, though, the physiological cause of addiction remains the same. Opioids, after being consumed, will travel through the blood brain barrier to attach to the mu opioid receptors on neurons. This connection causes the release of “feel-good” chemicals in the brain which result in an unnatural euphoria. This release of chemicals will combat pain, but the pleasure makes the drugs highly addictive, as users seek to replicate the feeling of pleasure, or the”high”.
Brain abnormalities are caused by the repeated overuse of opioids, as the brain becomes used to higher and higher levels of the pleasurable chemicals. The user can no longer experience pleasure without the aid of these drugs. With abusers, after one or two weeks off of opioids these abnormalities will disappear. However, with addicts, these abnormalities remain for their whole lifetime, due in part to genetic predisposition and environmental factors like social conditioning. Addicts will crave opioids for the rest of their lives, no matter how long they are clean.