My husband has problems or maybe early warnings of alzheimers. Needing to write everything down to remember it. mood changes, irritability, suspicions, vivid nightmares, etc. He has a family history of this disease. Many times lately conversations seem irrational and childlike. He is refusing medical advice and very suspicious of everything. Extremely defensive.
Welcome to Chat Doctor. These all are suggestive of psychological disturbances. It usually occurs due to chemical imbalance in the brain. I advise you to consult psychiatrist for better guidance and proper medical management as soon as possible. B12,vitamin, minerals supplement will be helpful. Give him active positive support. Make him busy with some activity if possible. Morning walk, yoga will be helpful. Keep in touch with your psychiatrist.