What Causes Bed Wetting And Introvert Behaviour In A Child?

Hi. My son is 13. He is still wetting the bed at least 4 nights a week. His legs and arms are normal size but he has a lot of body fat around the waist line. He is very self concious about being seen without a short. Locks the bathroom door and alwasy wears a baggy shirt. He doesn t verbalize it but it is obvious to me and my wife. The thing that concerns me, is that he is a great kid but seems to be withdrawing from friends...and is talking about not playing football next year. He has an easy to get along with personality but reacts over the top when disappointed. I am searching for ways to help him. Concerned that he may becoming depressed and the bedwetting also concerns us. Thanks, Kevin