Last updated: 05/1/2019
Author: Addictions.com Medical Review
Reading Time: 3 minutes
While not considered an illicit substance, nicotine’s effects on the brain carry an addiction potential that’s comparable to heroin and cocaine. According to the University of California–San Francisco, an estimated 45 million Americans smoke tobacco in one form or another.
As the leading cause of preventable disease and premature death, smoking embodies the essence of addiction as many long-time smokers well know the negative consequences associated with smoking. While you may have tried to stop smoking several time over, understanding how nicotine addiction actually works may help get you one step closer to getting needed treatment help.
How Nicotine Addiction Works
Nicotine has a chemical makeup that interacts with key cell receptor sites in the brain, also known as nicotinic cholinergic receptors. When nicotine enters the brain, it sets off a series of neurotransmitter processes, most notably dopamine, glutamate and GABA. These interactions set the stage for nicotine to alter chemical pathway functions in the brain.
According to the University of Maryland, nicotine acts as both a central nervous system stimulant and depressant simply because of the range of chemical changes it causes in the brain. With repeated use, brain chemical pathways auto-adjust to accommodate nicotine’s effects.
Every time brain chemical pathways readjust their outputs in response to nicotine’s effects, the brain’s dependence on nicotine increases. Under these conditions, it takes hardly any time at all to develop a physical dependence on nicotine’s effects
In the process, the brain’s overall chemical system develops a tolerance to nicotine, which makes individual cell receptor sites less responsive to the drug’s effects. When this happens, a person will likely increase his or her intake amount without even knowing it. These tolerance level increases can continue on indefinitely, driving users to keep upping their intake amounts.
Psychological dependence on nicotine occurs once the brain’s state of physical dependence and chemical imbalance starts to offset the brain’s reward system functions. In essence, someone who’s psychologically dependent on nicotine believes he or she can’t cope with daily life stressors without the drug’s effects.
This belief system develops out of marked imbalances in dopamine levels and the repeated surges of dopamine chemicals every time nicotine is ingested. Dopamine plays a pivotal role in regulating brain reward system functions, so nicotine’s effects have a pronounced effect on how the reward system views smoking behaviors in general. Once a full-blown addiction takes hold, a person experiences strong nicotine cravings, withdrawal effects and a sense that he or she “needs” nicotine to make it through the day.
Within any given year, 70 percent of people who smoke express a desire to quit. Out of this number, 40 percent actually do quit for a minimum of a day. On average, most people who attempt to stop smoking on their own return to smoking with in a month’s time, with heavy smokers only lasting for a few hours. Overall, only three percent of people who try to stop smoking actually succeed.
These trends reflect just how addictive nicotine can be. The longer a person keeps smoking, the harder it is to break the drug’s addictive hole.