My son was taking hydrocortisone up until January 1998 when it became obvious (and was confirmed by the annual bone xray), that puberty had started and although his calendar age was 11 and a half, his bone age was 15. The dosage of hydrocortisone was obviously not sufficient so we switched to Dexamethasone which is a steroid that is8 times "stronger" than hydrocortisone and is used by Endos in my country rather than Prednisone (a similar steroid), to establish control over an "escape" situation. In our experience, it did lead to mood swings, but that fluctuated as we had to amend the dose in line with the growth spurts associated with puberty (they cannot be predicted, so we were always after the event), but thats evidently always the case with CAH. Mood swings and weight gain were par for the course. Some of it had to be associated with the steroid dose situation, both over and under as puberty advanced. We have just decided to stop the Dex as things have stabilized, and go back to the Hydrocortisone, 3 times daily. This is to allow the growth hormone to have maximum effect as peer group pressure is a big thing we've found, especially as his older brother who does not have CAH is growing into a bean pole and Mark is concious that he will be lucky to make 5' 7inches.