Researchers led by Dr. Christian Montag at the University of
Bonn looked at the genetic makeup of 132 people who showed signs of
uncontrollable, self-destructive Internet use—in short, Internet addiction.
Compared to healthy individuals, the Internet addicts were more likely to have
a certain genetic variant that also plays a key role in nicotine addiction.
Internet addiction isn’t officially recognized as a diagnosis
yet, but an expert
panel has called for further study. There’s growing evidence that people who
have lost control of their online behavior act
a lot like addicts to nicotine and other drugs: They feel driven to keep
using the Internet, even when doing so leads to serious problems in their
lives. Plus, they’re preoccupied with the Internet, and they go through
withdrawal-like distress if it’s taken away.
Internet addicts spend hours online while neglecting their
jobs or relationships, and pack-a-day smokers puff away while destroying their
health. The similarity in behavior is easy to see. But this study suggests that
there may also be a hidden similarity.
In the brain, nicotine binds to the same receptors as
acetylcholine, a chemical that influences mood, attention, arousal, and memory.
These receptors are composed of proteins called subunits, and the blueprints
for making the subunits are provided by a handful of genes. Scientists have
found that variations in these genes can affect how easy it is for someone to
get hooked on smoking or how hard it is for a smoker to quit.
The Internet addiction study looked at a variant of a gene
called CHRNA4, which provides the blueprint for a subunit called Alpha 4. Past
research indicates that this variant may be a major player in nicotine
addiction. Now the new research suggests that it may be a factor in
Internet addiction, too.
It’s the first time scientists have looked at CHRNA4 in this context. But previous
studies linked Internet addiction to other genes affecting dopamine, a brain
chemical involved in feelings of pleasure, and serotonin, a brain chemical that
helps regulate mood. Those same genes are thought to influence alcoholism and
Nature and Nurture
One person spends 15 minutes online clicking the most interesting
headlines, and then closes the screen and gets on with the day. Another person starts
and can’t stop, despite work that is left undone and plans that wind up canceled.
The difference between the two, according to researchers such as Dr. Montag, could
be an addiction as real as any other.
Where chemical addictions are concerned, multiple genes may interact
to make someone more or less vulnerable. But factors such as behavioral
choices, emotional stress, and ready access to the addictive experience play a
crucial role in determining who actually gets hooked and who doesn’t.
That’s the way it is with cigarettes. And, for some people,
that may be how it is with the Internet, too.