Your brain is already dependent on 5-htp. 5-htp is what tryptophan breaks down into after digestion, and with co-factors produces serotonin. Tryptophan is found in any complete protein, and without it you'd be dead, so taking 5-htp is just increasing something you already have. The theory is it helps maximize the utilization of serotonin for those who need that, but it can have side effects, such as increased nervousness. It stops when you stop taking it. It won't affect adrenal health directly, but if you suffer from anxiety and/or depression and 5-htp reduces them, that will reduce stress on the adrenals. The only way you'll know if it will help is to try it, since your body's needs aren't someone else's needs and your reactions aren't anyone else's.
All you can do is gently try it and see how you feel. I do know that it takes a full 30 days to saturate and level out in your body. It is not a quick fix, so you may not notice anything different for a while.
Since it effects serotonin levels (I don't know how) can your brain get dependent on it 5 HTP ?