I have never done any cycles, staying all natural, but DHEA is usually used as a PCT after you do a cycle. Sometimes it can be used with a cycle to improve test levels, but usually the effect is minimal compared to other things you are sticking into yourself.
DHEA is supposed to help keep test levels high and help keep your libido after a cycle. Most people have mixed results, but commonly people claim to have a better sense of well being after taking it for some time.
These "test boosters" aren't worth taking imo ... by four weeks the boosted test release has aromatized to estrogen and it will shut down your natural test production until estrogen levels drop again.
Oh to actually answer your post:
Why feed your body things it really doesn't need?
I used to eat crappy ... hello entire package of Oeros and half gallon of milk in one sitting.
I used to have lower confidence then what I should have.
Never had any hormone issues though

~.
I start lifting and eating healthy and all I can say is my confidence has gone through the roof. I have gained significant muscle from a skinny 150 lbs frame to 210 lbs @ 6'1", and my confidence is just pouring out of me now. My hormonal level is insane I'm like a beast walking around looking for meat all day, every day. I have so much energy I can work out for hours and still have energy to do anything I want later in the day such as playing basketball. Lifting and eating well has changed my life, and I made that change with an all natural diet and the only supplements I use is whey protein because I can't afford steak for three meals every day.