Why do some people get addicted to things? As with most things in life, there are lots of causes, most of which have little, if anything, to do with genes or the brain. Getting high or drunk all day may be an appealing and even reasonable life choice if you're poor, bored and unemployed. It's less so if you've got a steady job, a mortgage and a family to look after.
On the other hand, substance addiction is a biological process, and it would be surprising if genetics did not play a part. There could be many routes from DNA to dependence. Last year a study reported that two genes, TAS2R38 and TAS2R16, were associated with problem drinking. These genes code for some of the tongue's bitterness taste receptor proteins - presumably, carriers of some variants of these genes find alcoholic drinks less bitter, more drinkable and more appealing. Yet ...
