My fiance suffers from a mental illness that includes mood symptoms as well as psychosis. It's something that can be managed but never fully "cured". One of my dear friends has Bipolar II, and is severely affected by it.

I think something that would help the average person react better to people with severe mental illness is a better idea of WHAT one should best do when confronted by a person's self-harming behaviour, suicidality or delusions. Because I think the average person WANTS to help, they just have no idea how. And not helping is seen as bad, especially if suicide and self harm are involved. Having four loved ones in several years express suicidal thoughts to me, one of whom actually attempted suicide multiple times, one of whom was not suicidal but was trying to manipulate me, and two of whom were "passively suicidal", the gut reaction I have is "leap into saviour mode, try and help them any way I can, and feel extremely guilty if I can't help, like I failed them". And so I've called helplines to ask for advice on what to say and how to best support people struggling with these symptoms. But a lot of people do not ask professionals how best to support their friends or loved ones with severe mental illness.

Maybe a public health campaign educating the general public on what to do if someone is suicidal or psychotic would be helpful? I'm not saying it's the job of the mentally ill themselves to educate people, just that I think a part of the stigma comes from people not knowing how to help, feeling helpless, and thus slipping into denial like "you must be feeling better NOW right? Right??" because if they are feeling better they now don't have any responsibility and they don't know what they'd do if they had the responsibility.