My friend said that they took a blood test and their bipolar disorder was "permanent", since I am a psychology student I know it is a mental disorder and does not show in the blood like a virus, but I always question myself so I want to know if I am possibly wrong. Or maybe they just got this blood test from a dodgy source, they said they didn't get it at a hospital.

So please help me with this, my friend is feeling very displeased about this and my word isn't enough to reassure them, since they have bipolar it could get unpleasant if they keep this idea in their head. Thank you very much for reading and thank you very much if you answer.