Sometimes, married life seems to invite disagreements, disputes, arguments, the silent treatment, all sorts of personal discord and turmoil.

At least that’s what a friend tells me.

But, it turns out, the good news is that marriage also seems to help prevent dementia, that ominous omnibus diagnosis that covers memory loss, personality and behavioral changes and disorienting loss of reasoning skills.

The bad news is that divorced individuals are more than twice as likely as marrieds to develop dementia, especially the men.

This is no minor concern. Experts on aging estimate nearly six million Americans currently live with Alzheimer and related dementias and their treatments cost some $290 billion annually

The new study was conducted at Michigan State University and is among the first such population-based U.S. research of variations in dementia diagnoses based on marital status.

The study sample consisted of 15,379 respondents — 6,650 men and 8,729 women. All were at least 52 years old in 2000 and symptom-free and examined every two years.

Researchers closely looked at four categories of non-marrieds — separated/divorced, co-habiters, widowed and never married. The divorced came out the worst for dementia.

The study’s head researcher, Hui Liu, noted, “Marital status is an important but overlooked social risk/protective factor for dementia.”

She added:

This research is important because the number of unmarried older adults in the United States continues to grow, as people live longer and their marital histories become more complex.

Other studies have shown that unmarried individuals have a higher risk of death from heart disease. One of those authors, Dr. Arshed Quyyumisaid, of Emory University said:

I was somewhat surprised by the magnitude of the influence of being married has. Social support provided by marriage, and perhaps many other benefits of companionship, are important for people with heart disease.

That companionship theme may have some under-appreciated health advantages. Previous studies have shown that owning a pet like a dog can extend human lifespans by promoting more social interaction and physical activity and reducing depression.

Elderly people with dogs, especially single elderly, were 33 percent less likely to die early. Quick plug for adoption: Google “pet rescue” with your Zip for the nearest shelter for dogs and cats. They’re lonely too.