I believe it to be the pressures of modern day life, when i've had a really stressful day, an alcoholic drink is the only thing that turns me off from it.
Delgirl, you are spot on. Alcohol enables relaxation and escape. Crack a can and the tension drains away. In this situation though, avoid computing your weekly 'recommended units' - very depressing.
if its all they think about when the first get up in th emorning then its generally to escape, but if its only say once a week at a party, its for fun.
either way both are easy to acquire so that helps their decision to indulge.