Situation 1: I just had a stressful day at work and a glass of wine or a cocktail is just what I need to unwind...GOOD IDEA
Situation 2: I just had a stressful day at work and a 12 pack and a hangover is what I need to unwind...BAD IDEA.
Drinking to relieve a mild stress is a fine idea, but drinking to deal with unhappiness or other more emotional stressors is definitely an unwise plan.