The following was written by Dr. Nora Volkow - a most important researcher and scientist. The way she writes about the brain and addiction is perfect and so, credited to her, I will just post it as she wrote it.
- A person takes a drug of abuse, be it marijuana or cocaine or even alcohol, activating the same brain circuits as do behaviors linked to survival, such as eating, bonding and sex. The drug causes a surge in levels of a brain chemical called dopamine, which results in feelings of pleasure. The brain remembers this pleasure and wants it repeated.
- Just as food is linked to survival in day-to-day living, drugs begin to take on the same significance for the addict. The need to obtain and take drugs becomes more important than any other need, including truly vital behaviors like eating. The addict no longer seeks the drug for pleasure, but for relieving distress.
- Eventually, the drive to seek and use the drug is all that matters, despite devastating consequences.
- Finally, control and choice and everything that once held value in a person's life, such as family, job and community, are lost to the disease of addiction.
What brain changes are responsible for such a dramatic shift?
Research on addiction is helping us find out just how drugs change the way the brain works. These changes include the following:
- Reduced dopamine activity. We depend on our brain's ability to release dopamine in order to experience pleasure and to motivate our responses to the natural rewards of everyday life, such as the sight or smell of food. Drugs produce very large and rapid dopamine surges and the brain responds by reducing normal dopamine activity. Eventually, the disrupted dopamine system renders the addict incapable of feeling any pleasure even from the drugs they seek to feed their addiction.
- Altered brain regions that control decisionmaking and judgment. Drugs of abuse affect the regions of the brain that help us control our desires and emotions. The resulting lack of control leads addicted people to compulsively pursue drugs, even when the drugs have lost their power to reward.
The disease of addiction can develop in people despite their best intentions or strength of character.
Drug addiction is insidious because it affects the very brain areas that people need to "think straight," apply good judgment and make good decisions for their lives. No one wants to grow up to be a drug addict, after all.
Co-occurring Addictions: Compounding Complexities
It is not unusual for an addicted person to be addicted to alcohol, nicotine and illicit drugs at the same time. Addiction to multiple substances raises the level of individual suffering and magnifies the associated costs to society. No matter what the addictive substance, they all have at least one thing in common - they disrupt the brain's reward pathway, the route to pleasure.