How often should a patient with vascular dementia mixed with Alzheimer's need to see their primary doctor?

IF you are just fine, the MD will say "see you next year". So if your friend is seeing the MD every month, he has health issues that are pretty darn serious. Worse, he will find another MD, not give him all the details and skip critical care. It's called "in Denial".
The patient in Memory Care is likely seen by the on site MD or NP and of course has daily nursing care. They probably will not have to go anywhere, care will come to them.

Primary care diagnosed, referred to Neurologist who medicated, ran EEG and MRI. Family member who is CNP suggested psychiatrist also. Thank you, I can contact primary Dr. He has been most helpful and experienced in geriatrics.

MsAngPat, if Mother seems depressed I would try to get her seen by a geriatric psychiatrist soon, and also keep the May appointment. Who diagnosed her?

My Mother diagnosed pre-dementia/alzeheimers in February and medicated.
Next visit to Neurologist is May. Family members in the medical field are suggesting Psycho evaluation, also saying that 3 mths is too long between visits. My Mother is in a depressed state, declining any interaction with family or friends, she doesn't eat right, no exercise and refuses to live with me. I have no siblings and my Father died with Picks. I am trying to make good decisions.
Any input is appreciated.

I think that your instincts are good, Sunnygirl1. I hope you find a geriatrician nearby for Mom's pcp.

Good ideas.
I wondered about that too and my family friend. He's on the thin side, and maybe he doesn't consider it a health problem, but maybe his doctor did. He says his new doctor says to come in only when he needs it. I'm considering his former doctor and his new one, since they both focus on the elderly.

The Memory Unit doesn't really have a doctor who comes to the facility. They transport to the doctor of your choice. I moved her there in October and now need to get her a new doctor that is closer to the facility. Her existing one is over an hour away and he wants to see her about every other month,. I have no issue with it, if it's necessary, but not if it isn't.

I'm also going to get her to a geriatric psychiatrist that sees a lot of the Memory Care residents. I want to see if there are any medications that might help her maintain. She's lost some ground, but still has her verbal and feeding skills.

Is your cousin seen regularly by a dementia specialist? If he or she is in a memory care unit and they are monitoring the diabetes and health in general I would think that seeing the primary care doc would be on an as-needed basis, or possibly routinely once or twice a year. What does the pcp suggest? The memory care unit probably also has an on-staff doctor. Does that doctor visit regularly?

My husband lived at home, was treated for dementia by a specialist, had several other health concerns, and generally saw his pcp about once a quarter. Sometimes if he was stable and doing well she would suggest his next appointment be in 6 months.

On the face of it, your family friend is being asked to come in very frequently. But there may be some issues that you are not aware of that the pcp legitimately wanted to keep an eye on. Over use of pain meds, suspicion of addiction, early sign of dementia ... who knows? But your friend is certainly entitled to change doctors if he is not comfortable with the one he had.

There may be some standard guidelines that someone in the healthcare profession can share with us. But I also think it is highly dependent on specific circumstances.