being caught with drugs implies that you were trying to conceal them, admitting to using them is obviously the opposite. i'm not really sure what you mean by outcome so i'm going to assume you are referring to the police. generally if you are honest with cops they will work with you, unless of course you are carrying your entire stash around with you. but if you try to hide your drugs and they find it, they will have no intention of cutting you slack. and of course there's always the possibility they won't find it, which is rare when k9 is involved.
so in conclusion: honesty is the best policy. but avoiding the situation is an even better one