Nicotine Addiction

Nicotine is the chemical in cigarettes that makes them addictive. Higher levels of nicotine in a cigarette can make it harder to quit smoking. A report by the Massachusetts Department of Health found that the amount of nicotine in cigarettes has steadily increased over the last 6 years. Higher nicotine levels were found in all cigarette categories, including 'light" brands. Massachusetts is one of several states that require tobacco manufacturers to submit yearly reports regarding cigarettes.

Some researchers feel nicotine is as addictive as heroin. In fact, nicotine has actions similar to heroin and cocaine, and the chemical affects the same area of the brain.

Depending on the amount taken in, nicotine can act as either a stimulant or a sedative. Cigarette smoking has definite immediate positive effects. For example, it can:

* Boost mood and relieve minor depression
* Suppress little fits of anger
* Enhance concentration and short-term memory
* Produce a modest sense of well-being

Most smokers have a special fondness for the first cigarette of the day because of the way brain cells respond to the day's first nicotine rush. Nicotine, particularly taken in the first few cigarettes of the day, increases the activity of dopamine, a chemical in the brain that elicits pleasurable sensations, a feeling similar to achieving a reward.

Over the course of a day, however, the nerve cells become desensitized to nicotine. Smoking becomes less pleasurable, and smokers may be likely to increase their intake to get their "reward." A smoker develops tolerance to these effects very quickly and requires increasingly higher levels of nicotine.

A smoker may "forget" their craving for nicotine if a part of the brain called the insula becomes damaged. A 2007 study published in the journal Science found that smokers with brain damage to this area were 136 times more likely to forget their addiction to nicotine. The findings may one day lead to new drugs that better help a person quit.