Well it depends on the problems you mean, for example, sex can ruduce mental and emotional stress, it produces Oxytocin that is quite beneficial in reducing the blood pressure, boosting the immune system and keeping the mind sharp and alert.

However when there is marital or work problem, people switch to things like alcohol and sex like you suggested

And this will definitely take the mind off these problem for a while, HOWBEIT it doesn't get the problem solved.

Problems are always there unless we face them and look for plausible solutions that can be lasting, using sex when there is a problem, is like going around a wall for the mean time but the lasting solution will be going through it which means seeking a more better solution for a problem.

Sex doesn't solve problems it's only a recipe that take your mind off the problem for just only a while.