Trust is the firm belief in the reliability of someone or something. You can trust your mother — you can trust her to be mentally ill.
I don’t know if she has any moments when she is lucid enough to know she needs help. I had a relative who was mostly unaware — but he had moments — moments of great grief when he would wish he wasn’t that way. Medication never helped. It doesn’t help everyone.
I’m sorry you have to deal with this. It’s not easy for anyone involved.