Examining the brains of deceased alcoholics who smoked, researchers found drinkers who also smoked derived more pleasure from each activity individually, making both harder to quit. "Alcoholics often have a particularly hard time quitting cigarettes. Traute Flatscher-Bader at the University of Queensland in Brisbane, Australia, and colleagues wondered why this should be. So they did a post-mortem analysis of gene expression in the brains of smokers, alcoholics and those who had done both during their lives." The analysis is more than a social survey, says the New Scientist: "Knowing that the link between drinking and smoking may not be purely social could lead to new ways to treat addiction."