I have used Mirena for 20 months now and I can say it is an excellent method of contraception. I have been on numerous types of pills that didn't agree with me, they made me constantly moody and irritable. I can say that Mirena has made my cramps better, periods lighter, sometimes I don't get a period. However while browsing the Mirena website at www.mirena-us.com it states that it is recommended for woman who have had at least one child and who are in a committed monogamous relationship. I am in my late 20's, and have no children, have been married for 4 years and I can say that is hasn't decreased my sex drive or made me depressed in any way.
It may be worthwhile to check out the website and consult your doctor. Good Luck.