I fully agree with you Aglutinous ... When family or friends?? abstain from morally supporting the ataxia sufferer, that alone can cause stress, thereby enhancing the ataxia. Additionally, awareness of other negative environmental factors heavily add to the equation.
The bipolar debate etc. in this case, is something the medical brigade is slow on the uptake.
I have a short temper and end up yelling at my wife for the dumbest things. Later I feel terrible about it. I would say yes, Ataxia causes mood swings.
My experience with Ataxia is that it doesn’t necessarily cause mood swings as such but does cause Depression. Mood swings and anger are part of depression. I didn’t take an antidepressant, and snapped out of my depression once I started feeling better as a result of accepting my disease and its limitations. Neurologists are not psychologists or psychiatrists but are more than happy to prescribe anti-depressants. All I’ve read says these drugs should not be used alone without counseling. And it’s possible he’s not depressed but has simply changed his mind about being in the relationship and can’t be direct about it. Perhaps the doctor can give you a referral to a psychologist to make the determination about what is really happening. Certainly counseling for anyone dealing with Ataxia is not an unreasonable request.