The doctor, with no tests, declared him healthy and doesn't have dementia! What can I do next?

I wrote a letter and followed up with a call to his doctor. A psychologist diagnosed him 10 years ago of dementia and he is so depressed and angry now and I wanted his new VA doc. to give him some "happy" pills. He ignored me completely and told my husband to try to get along better with me. He tried to commit suicide two years ago he was so depressed. His doc. just doesn't want to deal with him. Or me. I thought I was lucky to get him to a doc. with his permission who would help, what can I do next? He is in the VA system and refused to go outside the system.