I don't have bipolar, but prednisone makes me psychotic and suicidal when I take it orally or by IV. (I've had to take it for an autoimmune disease.) However, if you're talking about steroid injections into a joint (I assume that's what you're talking about since you mentioned lumbar issues), those have never had that effect on me. I had five steroid injections in my lumbar spine and sacroiliac joint over the course of about 18 months with no side effects, and they did help a lot with my pain levels. I know that's just anecdotal, but I thought it might help.