| Nicotine is a highly
addictive psychoactive chemical. When tobacco is smoked, most of
the nicotine is pyrolyzed; a dose sufficient to cause mild
somatic dependency and mild to strong psychological dependency
remains. According to studies by Henningfield and Benowitz,
overall nicotine is more addictive than cannabis, caffeine,
ethanol, cocaine, and heroin when considering both somatic and
psychological dependence. However, due to the stronger
withdrawal effects of ethanol, cocaine and heroin, nicotine may
have a lower potential for somatic dependence than these
substances. A study by Perrine concludes that nicotine's
potential for psychological dependency exceeds all other studied
drugs - even ethanol, an extremely physically addictive
substance with severe withdrawal symptoms that can be fatal.
About half of Canadians who currently smoke have tried to quit.
McGill University health professor Jennifer O'Loughlin stated
that nicotine addiction can occur as soon as five months after
the start of smoking.
Recent evidence has shown that smoking tobacco increases the
release of dopamine in the brain, specifically in the mesolimbic
pathway, the same neuro-reward circuit activated by drugs of
abuse such as heroin and cocaine. This suggests nicotine use has
a pleasurable effect that triggers positive reinforcement. One
study found that smokers exhibit better reaction-time and memory
performance compared to non-smokers, which is consistent with
increased activation of dopamine receptors. Neurologically,
rodent studies have found that nicotine self-administration
causes lowering of reward thresholds--a finding opposite that of
most other drugs of abuse (e.g. cocaine and heroin). This
increase in reward circuit sensitivity persisted months after
the self-administration ended, suggesting that nicotine's
alteration of brain reward function is either long lasting or
permanent. Furthermore, it has been found that nicotine can
activate long term potentiation in vivo and in vitro. These
studies suggests nicotine’s "trace memory" may contribute to
difficulties in nicotine abstinence.
Mood and anxiety disorders
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Tobacco smoking
Methods of smoking
Health effects
1.
Establishing a link between smoking and health effects
2. Health risks of smoking
2.1 Carcinogenicity
2.2 Effects on the heart
2.3 Smoker's attitudes
3. Passive smoking
4. Somatic and psychological effects
5. Mood and anxiety disorders
6. Health benefits of smoking
Effects of the habit and
industry on society
1. Effect on healthcare costs
2. Tobacco and other drugs
3. Advertising
4. Peer pressure
5. Parental smoking
6. Smoking in movies and television
7. The use of smoking to project an image
Religious views
on smoking Smoking cessation
Legal issues and
regulation
1. Age restrictions
2. Taxation
3. Restrictions on cigarette advertising
4. Package warnings
5. Smoking bans
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