Researchers say that people who drink are often those who smoke because the centre in the brain that derives pleasure from both these actions is the same.
Traute Flatscher-Bader at the University of Queensland in Brisbane, Australia, and colleagues did a post-mortem analysis of gene expression in the brains of smokers, alcoholics and those who had done both during their lives.
"They observed that a group of genes in the nucleus accumbens - an area involved in creating pleasurable feelings - were expressed most strongly in their group of alcoholic smokers.According to Flatscher-Bader, these genes play a role in rewiring the neurons in the nucleus accumbens. That means people who both smoke and drink might get a greater reward, making it harder for them to quit," reports New Scientist.
The study has been published in Alcoholism: Clinical and Experimental Research.