While I have no personal experience with dex specifically, I have undergone high dose steroid therapy in the form of doxorubicin, the D in VAD- doxorubicin therapy really threw me for a loop when I was on this therapy- not only did I feel UP when I began the therapy and DOWN when i came off the therapy, I gained almost 50 pounds during the 4 months while I was on VAD and developed cataracts in both eyes- a common side effect of high dose steroid use.