Hi,
How are you doing now? My husband has had Myasthenia for 3 years. We are currently trying to wean him off the Prednisone because we also think that it is making his symptoms worse. It takes a long time though. The second day that he took the Prednisone we became aware of the mood changes. It helps to know that you're feeling depressed or angry because of the medicine, our neuro did not warn us to expect this. His dosage was increased after an allergic reaction to IVIG. Since then he has developed the "moon face", extreme fatigue, weight gain, muscle cramps, muscle atrophy and sleep problems. We have halved the Prednisone over the last few weeks and so far we have noticed no change. It certainly hasn't made his symptoms worse. Not sure how long it takes to get it out of your system.