P-450 2A6) or even polysubstance abuse (polymorphism
of TaqIA D2 dopamine receptor gene).
- Age: early exposure to drug use significantly in-
creases the risk of addiction, particularly during adoles-
cence. It is a period of ongoing brain development and
therefore particularly sensitive to the effects of drugs; it
is also a period of enhanced plasticity and during which
the underdeveloped prefrontal regions necessary for
adult-level judgment cannot properly regulate emotion
yet.
Particularity: addiction to money games and video
games
After years of denying their existence, scientists recently
started recognizing and studying these modern forms of
addiction. As a matter of fact, in 2013, gambling has been
classified in the DSM-5 as a form of addiction. This shift
in scientists’ attitude is mainly due to researches that
demonstrated that the biologic definition of addiction –
i.e. changes in neural circuits – clearly applies to these
particular forms. However, the psycho-social factors are
way more important in this case than in drug addiction.
As in the case of gambling, animal models have
shown that a complete random reward is one of the
strongest reinforcers of the neural circuits. All money
games are specifically designed to stimulate this unpre-
dictable reward and excitement. Furthermore, gamblers
tend to trap themselves by figuring out wrong ideas
and concepts about the game; one of the most popular
mistake is to think that they somewhat have the pow-
er to change the results by throwing the dices with a
different strength or shuffling the cards themselves, etc.
This illusion of power further increases the excitement.
A tolerance state is rapidly reached and the gambler no
more feels the excitement of putting himself in danger,
resulting in constant increases in the amounts of money
put in the game.
In the case of video games, the addiction seems
to be related to the personality and social problems of
the gamer. It is a way for them to run away from their
reality and become someone else. It’s not surprising
then that the MMORPGs are among the most addictive
games, where the gamer can enroll a fantastic charac-
ter with whom he can interact with people, make friends
and even be a hero or a leader; all are pleasures that he
failed to accomplish in real life.
References:
1 - Kandel, E. R., Schwartz, J. H. 1., &Jessell, T. M. (2000). Princi-
ples of neural science (4th ed.). New York: McGraw-Hill, Health
Professions Division.
2- Diagnostic and Statistical Manual of Mental Disorders
(DSM-5). American Psychiatric Association. Arlington American
PsychiatricPublishing; 2013.
3- CENEAP (Centre National d’Etude et Analyse pour la Popu-
lation et le Développement), 2013.
4- Cami J, Farre M. Drug addiction. N Engl J Med.
2003;349(10):975–86.
5- Volkow ND, Koob GF, McLellan AT. Neurobiologic advances
from the brain disease model of addiction. N Engl J Med. 2016
Jan 28;374(4):363–71.
6- Nutt DJ, Lingford-Hughes A, Erritzoe D, et al. The dopamine
theory of addiction: 40 years of highs and lows. Nat RevNeuro-
sci 2015;16:305–12.
7- Blaise M, Grégoire M, Valleur M. Addictions à l’héroïne, à la
cocaïne, au cannabis et autres substances illicites. EMC - Psy-
chiatrie 2017;14(4):1-18 [Article 37-396-A-40].
8- Valleur M, Codina I, Rossé E. Addictions sans produit. EMC -
Psychiatrie 2016;13(1):1-11 [Article 37-396-A-20].
9- Schultz, W. Predictive reward signal of dopamine neurons. J.
Neurophysiol. 80, 1–27 (1998).
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