Internet Addiction Partially Genetic? CHRNA4?

[Scarlet Ibis]

http://www.ncbi.nlm.nih.gov/pubmed?term=internet%20addiction%20chrna4


Abstract
Recent studies from Asia provided first evidence for a molecular genetic link between serotonergic and dopaminergic neurotransmission and Internet addiction. The present report offers data on a new candidate gene in the investigation of Internet addiction-the gene coding for the nicotinic acetylcholine receptor subunit alpha 4 (CHRNA4). A case-control study was carried out. The participants were recruited from a large gene data bank, including people from the general population and from a university setting. A total of 132 participants with problematic Internet use and 132 age- and sex-matched controls participated in the study. Participants provided DNA samples and filled in the Internet Addiction Test Questionnaire. The T- variant (CC genotype) of the rs1044396 polymorphism on the CHRNA4 gene occurred significantly more frequently in the case group. Further analyses revealed that this effect was driven by females. Combined with the findings from other studies, the present data point in the direction that rs1044396 exerts pleiotropic effects on a vast range of behaviors, including cognition, emotion, and addiction.

[Phil75231]

If this gene does exist, then it might be linked to visual/audio excitement in general. Pre-Internet, people certainly got addicted to TV. Before that, I'm sure some got addicted to radio as well. Also, I'm sure the researchers controlled for this, but ADD tends to operate well in an environment where you can "change the channels" quickly, whereas many often don't do well in situations requiring one to sit down and listen to a conversation for a long time (I've heard it said that TV is tailor-made for ADDers).

This gene might be part of a deeper tendency toward excitement / sensation seeking in general (i.e. addicted to excitement). If the gene's implicated in creation of neurochemicals, those neurochemicals may be perfectly natural for our brains, but nevertheless the neurochemicals are mind-altering substances.

It's precisely for this reason I try to keep excitement in my life to a minimum (I don't mean "activities that generate excitement", I mean the emotion itself).

[Ezana]

Interesting, Scarlet. Its putative importance would be a lot broader than just getting pleasure from the internet, though. Acetylcholine is a neuromodulator throughout the brain (however, I'm not sure where a4 nAch receptors are most prevalent). Unfortunately, there are a ton of these variants that could be significant whose roles we're still very far from uncovering.