Alzheimer's and Social Stimulation

---Full disclosure: I am not what most people consider a "social person" and that is likely to color the contents of this post.---

Lack of social contact is considered one of the greatest risk-factors for developing Alzheimer's Disease. Like many things that "everybody knows", close examination reveals that the connection is not crystal clear.

The major reason for the lack of clarity is that cause-and-effect are very muddled.

In many, perhaps most mental-health issues, pathology is not suspected and a clinical diagnosis is not warranted as long as the patient's lifestyle is not significantly impacted. "Sadness" is not sufficient reason to trigger a diagnosis of "Depression" but being unable to leave your bed and getting fired from your job is.

But it isn't just the patient. Other people who experience extreme inconvenience is enough to be the catalyst that starts the cascade of events that results in a "diagnosis". Those people can be the patient's caregivers, family or other responsible "parties".

Inability or extreme aversion to interaction with humans in the public sphere are one of the symptoms that can cause other people extreme inconvenience.

If withdrawal from social interactions is one of the prime symptoms that funnel patients into a diagnosis of Alzheimers then it is improper to consider social withdrawal to be a cause. "Oh, look. The tomatoes are ripe because they are red. Everybody knows that red makes tomatoes ripe."

No matter how thinly you slice it...

There are limits to what science can "see".

Suppose that you believed that excessive consumption of trans-fats increased the risk of developing heart-disease.

Most forms of shelf-stable coffee whitener are mostly trans-fat by non-water weight.

Ergo, people who put creme in their coffee should have higher rates of heart-disease. Alas, no study has ever found that eliminating shelf-stable coffee whitener has had any effect on heart-disease even though everybody knows it should.

The problem is too much noise and too little signal. One mouse turd in one-hundred pounds of black pepper.

That is the first fist that punches science in the nose when attempting to back-out the degree to which social interactions provides a protective effect against Alzheimer's.

Another punch-in-the-nose is from the difficulty in quantifying "social interaction'. It isn't like green tea where you can run an experiment where one cohort consumes five-grams of green tea a day and another cohort consumes none.

The efforts to quantify or characterize social interaction further splinters the signal but does little to reduce the noise.

Is the determinant form of "social interaction" language or analytical? Is it physical touch or motion or visual? Is it deep interactions with one or two people or is it superficial interactions with many more? Is it interactions in our youth or middle-age or while we are dancing on the brink of dementia? Too many questions. Not enough signal.

(Ageing without dementia: can stimulating psychosocial and lifestyle experiences make a difference?)

Where do we go from here?

Progression of our mental-models of information as we age. Youngest models on the left, more mature models on the right.

What if we start from the beginning?

The illustration shown above is a conceptual drawing of how we accumulate information.

The circle on top is the "bobber" like the kind used for fishing. Or, if you ever programmed in Pascal it is the "handle" and the circles that dangle downward are the rest of the record.

For normal people who never programmed in Pascal, the circles shown below the "bobber" are "the answer" or a chain of related pieces of information.

In our youth, we are fed information in straight, unbranching drill-downs.

At some point, we realize that information is not linear and our brains have matured to the point where we can conceptualize and store information in  branching structures similar to tree roots.

With adulthood, we start cross-linking the root-like structures. We realize that geometry and algebra can be useful when building a fence. We can look at a small thumbnails and we can make surprisingly accurate guesses about what the rest of the panorama looks like.

As we age, we run into problems maintaining the linkages. They are not indelible and they fade if they are not refreshed on a frequent basis. In dementia, the linkages are vaporized by cell-death. If it helps, it is as if sectors of the directory on the hard-drive are irreparably corrupted.

If, however, the important information is sufficiently cross-linked then redundant paths to that information exist. They can be found (what do you think is happening when we dream?), refreshed and the brain can continue to function with minimum impairment.

The money line

A wide range of social interactions increase the odds of our refreshing a broad portfolio of cross-links and thereby partially armoring our brains against the inevitable ravages of time, orgies, drugs and rock-and-roll.

Or if you are like me...the inevitable ravages of time.

You can take it as a matter of faith and expose yourself to social interactions or you can wait until science sorts it out. What is the worst that can happen? You fall in love with cannoli and baklava?

Bonus advice: The link between hearing loss and Alzheimer's might be that we withdraw from social events if we cannot make sense of conversations. So whether we attend in body but cannot benefit from the stimulation because we cannot hear or if we stop attending because we are embarrassed, the end result is the same; we lose the benefit of having our cross-links refreshed.