All it takes is one
Up to now, it was thought it took a few
years for smokers to become addicted, but the latest research
shows addiction takes place in days.
Scientists have confirmed a suspicion
held by some smokers but never proven: it could take just one
cigarette to become addicted.
Experts have tried for years to determine how long people have
to smoke before becoming addicted, said Dr Richard Hurt,
director of the Nicotine Dependency Unit at the Mayo Clinic in
the United States.
"The best answer to date has been one to
two years," said Dr Hurt, who was not involved with the latest
research. "There's been a suspicion that many people become
addicted very quickly, but this is really the first hard
evidence that we've had that this occurs."
Research reported in the British Medical
Association journal, Tobacco Control, found that several 12-
and 13-year-olds showed evidence of addiction within a few
days of their first cigarette. Dr Hurt said the findings would
help scientists better understand the biology of nicotine
addiction and lend more plausibility to the idea that some
people may be more susceptible genetically to it than others.
The study was conducted by scientists at
the University of Massachusetts in 1998. The experts followed
681 teenagers aged 12 and 13 from seven schools in central
Massachusetts for a year and tracked their smoking habits.
The researchers did not label any of them as addicted because
the standard definition of nicotine dependence assumes that
addiction cannot happen without prolonged heavy smoking. The
scientists simply recorded symptoms that indicate addiction.
Symptoms include cravings, needing to smoke more to get the
same buzz, withdrawal symptoms when not smoking, feeling
addicted to tobacco and loss of control over the number of
cigarettes smoked or the duration of smoking. A total of 95
teens said they had started smoking occasionally - at least
one cigarette a month - during the study.
The scientists found that 63 per cent of
them had one or more symptoms of addiction. A quarter of those
with symptoms got them within two weeks of starting to smoke
and several said their symptoms began within a few days.
Sixty-two per cent said they had their first symptom before
they began smoking every day, or that the symptoms had made
them start smoking daily.
"The really important implication of this study is that we
have to warn kids that you can't just fool around with
cigarettes or experiment with them for a few weeks and then
give them up," said Dr Joseph DiFranza, who led the research
If you fool around with cigarettes for a
few weeks, you may be addicted for life.
How Does the Body Become Dependent on Nicotine?
Every time we light up, nicotine and other
chemicals from cigarette smoke are absorbed in the body.
Nicotine enters the bloodstream and reaches the brain faster
than drugs that enter the body through our veins. Nicotine
affects many parts of the body; it changes how the body uses
food (metabolism), causes our heart to beat faster, our pulse
to quicken, it increases our blood pressure, and our veins
begin to tighten causing blood flow throughout the body to
become more difficult.
Nicotine works by stimulating our nervous system to release
specific chemical messengers (hormones and neurotransmitters)
that affect different parts of our brain and body. One hormone
that nicotine affects is epinephrine, also known as
adrenaline. When nicotine is inhaled, the buzz you feel is the
release of epinephrine which stimulates the body and causes
your blood pressure and heart rate to increase, and makes you
breathe harder. Nicotine also activates a specific part of
your brain that makes you feel happy by stimulating the
release of the hormone dopamine. The release of dopamine when
nicotine is inhaled is thought to be the source of the
pleasurable sensations you experience when smoking, which can
include relaxation, a buzz, and relief of tension.
Once inhaled, nicotine is rapidly
distributed throughout the brain within 10 seconds. The
enjoyable feelings you experience from smoking occur very
quickly, but after you’ve smoked a few times nicotine begins
to weaken your ability to feel pleasure, causing you to need
more nicotine in order to sustain the good feelings. This is
the cycle of the smoking habit; in order to continue feeling
pleasure from smoking, you must continue to smoke more
cigarettes, more frequently.