I had a steroid injection ( intramuscular for body wide pain) at the beginning of the month. I have ankylosing spondylitis. A few days later my mood plummeted. It just got worse to point of suicidal. Thanks to a good friend ( psychiatric nurse) I contacted my GP and got help. Know one can tell me how long the steroid will affect me like this. Does anyone know? Has anyone had a similar reaction?