What is heroin addiction?
Heroin addiction like all opiate addictions occurs when heroin is administered over a sustained period of time. The onset of heroin addiction can be both rapid and severe, dependent on the amount used and frequency in a designated period of time. Heroin addicts will “crave” more of the drug and experience withdrawal symptoms if they do not get their regular “fix” or dose. Not all of the mechanisms by which heroin and other opiates affect the brain are known. Likewise, the exact brain mechanisms that cause tolerance and addiction are not completely understood. Heroin stimulates a “pleasure system” in the brain. This system involves neurons in the mid-brain that use the neurotransmitter called “dopamine.” These mid-brain dopamine neurons project to another structure called the nucleus accumbens which then projects to the cerebral cortex. This system is responsible for the pleasurable effects of heroin and for the addictive power of the drug.
