my first reaction was to think this thread was kind of dumb, so i didn't post... but i keep thinking about it.
i don't think most people are really even happy, and it's more someone is content if they are best off... at a point i think heroin is probably going to get boring for a lot of people, so i think it's probably more of a form of relief... i think someone can go through the ups and downs of being addicted, and be just as content as a regular person.... it's more about the person's perspective and nartural chmical balance (some people deal with drugs easier than others or enjoy them more)... this is totally not a cut and dry question, although i think the OP was just looking for experiences and thoughts as opposed to a definite answer.
i rarely ever see people that come across as happy when i go out in public. i recognize people that appear to be content and might be feeling better than others.. but i generally don't see what appears to be happiness. some people come across more interested or engaged with others, but i'm not sure that's a sign of happiness... i think most people that experience true happiness probably have mental disorders similar to bi-polar... in a society like ours, there's always stuff to bring people down. i think how fucked up the world is causes a lot of mental health issues. what we see in society doesn't promote people to be able to feel their best... sometimes drugs help people ignore that and they feel better off. opiates are some people's DOC... i don't see why a drug free person would be better off than a hard drug user, especially opiates where if you have a clean supply you know you aren't at risk... if a person is gambling their life using cut shit then i'd probably guess they probably aren't thinking as well.