I cared for my mother, who moved in with us, and found that the best advice I got was to keep calm myself and keep the words "don't you remember" or "remember when". Just talk about the subject/memory. She was able to calmly share things about her childhood that shame had made her keep secret for the rest of her life. I tested the waters carefully with such questions as "what games did you play with your sister (her twin who died when she was 6) and learned some of the things he mother had done as a result. It explained a lot of her behavior all her live, but didn't upset her to talk about her. She, however, didn't have paranoid issues, which would be reason for extra caution.

This may sound off the wall, but it is harmless. Vitamin B12 deficiency can cause some of the symptoms you describe. This is why memory deterioration can occur with alcoholism. An under the tongue supplement used as directed may or may not help. In swallowed form it is less effective if at all because of the effect of aging on the absorption of it, but swallowing works well for the other helpful B vitamins. It helped my mother-in-law for a time.