My friend has been through hell and back with doctor prescribed medication cocktails the past fifteen years. There were certainly times a firearm within reach would not have been a good idea, although now things have stabilized tremendously.
I'm on the fence about the whole mental health/gun ownership thing. On one hand there are plenty of people that shouldn't be anywhere near a gun, but the flip side is mental health professionals are so eager to diagnose pretty much everyone with a disorder and treat you like a guinea pig.
I also suspect some gun owners will be skipping appointments for fear their psychiatrists will report them to the courts. Right now they can do this only if you expressed actual threat to harm oneself or others. This will change.