Addiction

Nicotine, one of more than 4,000 chemicals found in the smoke from tobacco products, is the primary component in tobacco that acts on the brain. Since nicotine was first identified in the early 1800s, it has been studied extensively and shown to have a number of effects on the brain and the body.

Nicotine is addictive. Addiction is characterized by compulsive drug-seeking and use, even in the face of negative health consequences, and tobacco use fits the description. It is well also documented that most smokers identify tobacco as harmful and express a desire to reduce or stop using it, and many make serious attempts to quit each year. Long-term success rates are, however, low.

Recent research has shown how nicotine acts on the brain to produce a number of behavioral effects. Nicotine is known to activate those parts of the brain that regulate feelings of pleasure, the so-called reward pathways. A key brain chemical involved in mediating the desire to consume drugs is the neurotransmitter dopamine. Research has shown that nicotine increases the levels of dopamine in the brain.

Cigarette smoking is the most prevalent form of nicotine addiction. Through inhaling smoke, the average smoker takes in 1 to 2 mg nicotine per cigarette which reaches the brain within 10 seconds. However, the acute effects of nicotine dissipate in a few minutes, causing the smoker to continue dosing frequently throughout the day to maintain the drug's pleasurable effects and prevent withdrawal.