Should i take dhea if it seems to help my mood?

No: Dhea is metabolized to cortisone, estrogen and testosterone -- and you can't control which one is goes to. Also, there is no medical indication to take it in the first place, and most of the dhea supplements have little dhea in them. Don't get your medical advice from tv or the internet!

Hormone replacement: Its never a good idea to take a hormone as a supplement unless there is a deficiency. Even in some hormone deficiencies, the drawbacks to replacement outweigh the benefits. While there is some limited evidence that dhea replacement can help specific groups (people with addison's disease for example), I am unaware of evidence for pregnenolone replacement. Endocrinologists have this knowledge.