Depends on the trade and how much work/workers needed there are. If there is a shortage of workers it doesn't seem to matter for most, so long as you can show up and perform half way decent.
But most important thing is honesty. Not saying you should tell every little detail, sometimes things like an old drug habit might be best to leave out of the picture/interview. you can always go with something like family problems/issues that you had to deal with and help out or be there, yadayada. IME, there are a lot who are sympathetic of this as opposed to a drug habit. Also, something like that it is easy to pretend that it is a somewhat touchy subject and you'd rather not talk about it.
If you have been out of work for a while and don't have very many job specific skills you might have to take whatever comes your way and build up from there. Could always use the job for references and use the money for college classes or trade school for something you want to do.