A couple of months ago, a man approached me on the street near my home. He asked for a bit of money, and although I usually never do, for some reason I gave it to him. I later saw him on a regular basis near the neighborhood grocery. I found out his name was John* and he used to work in construction. Several times a week, I’d run into him and stop and chat for a few minutes.

One day, I noticed he had large purple bruises on his forehead. He told me he had tripped over his shoelaces and gone down hard. Especially if someone is exhausted and cold, it’s easy to see how this could happen. He had been to the hospital, but they dismissed him quickly, perhaps because he was homeless.

He had lived in our town for 48 of his 53 years, and only become homeless recently after losing his job, like so many others. It troubled me to think that after a lifetime of contribution, our town had cast him aside so readily.

I was reminded of John yesterday when I heard that over half of homeless people may have brain injuries. Skeptical, I decided to do some digging. I found a metanalysis in The Lancet that confirmed this astounding figure:

The lifetime prevalence of any severity of TBI [traumatic brain injury] in homeless and marginally housed individuals (18 studies, n=9702 individuals) was 53.1%

This is much greater than the general population:

The lifetime prevalence of TBI in homeless and marginally housed individuals is between 2.5-times and 4.0-times higher than estimates in the general population. Moreover, the lifetime prevalence of mo­derate or severe TBI in this population is nearly ten-times higher than estimates in the general population.

It’s difficult to say whether the brain injuries are a cause or effect of homelessness. But, homeless people tended to have their first TBI at a young age. To me, this argues that brain injuries are a cause of homelessness:

Age at first TBI ranged from 15 years to 19.9 years, and we calculated a weighted mean age of first TBI of 15.8 years.

Perhaps the relationship works both ways:

TBI could increase the risk for homelessness, and homelessness could increase the risk for incident TBI.

It’s common for us to blame the homeless for their condition. After all, many are addicted to alcohol and drugs, aren’t they? But that too may be related to head trauma:

several characteristics of homeless and marginally housed populations (eg, residential instability or substance use) were associated with sustaining TBI

Another study from Canada found similar figures, and noted that the first TBI usually happened before they became homeless:

The lifetime prevalence among homeless participants was 53% for any traumatic brain injury and 12% for moderate or severe traumatic brain injury. For 70% of respondents, their first traumatic brain injury occurred before the onset of homelessness.

A British study found that homelessness was not a significant predictive factor for head injuries. However, it didn’t address the question of whether the homeless had a TBI before becoming homeless.

Imagine two people, one with an stable and well-off family and one with a chaotic and impoverished family (or no family at all). They both hit their heads. One gets support and good medical care, but the other may wind up homeless.

I sometimes wonder if that’s what happened to John. Did he get hurt, wind up homeless, and then find himself in a position to get hurt again?

I haven’t seen him lately, despite looking for him over and over. I hope he found a nice place to stay this winter, and I hope to see him again.

If you found this post interesting, please share it on Twitter/LinkedIn/email using the buttons below. This helps more people find the blog!

*Not his real name

Photo: “Thomas (Tomaso) is Homeless” by Franco Folini is licensed under CC BY-SA 2.0