Depression and Dementia

(Image from sharpbrains.com)

As if life wasn't difficult enough for teens and young adults with depression, UCSF researchers say that this condition is highly correlated with dementia. [bold added]

Depression in young adulthood might increase risk for cognitive impairment in old age, a new UCSF study has found.

The study — which used predictive models to determine depressive symptoms over a lifetime — found that the chances of cognitive impairment were 73% higher for those estimated to have elevated depressive symptoms in early adulthood, and 43% higher for those estimated to have elevated depressive symptoms in later life.

The conclusions find a receptive audience because they play into our belief that brain disorders are related. However,....

1) There are a great many years between youth and old age. Youthful disease is not destiny.

2) Depression is better understood today than in the past. Therapy and changes in attitudes and behavior (gratitude, social interaction, self care, hobbies, and "cognitive restructuring") can help, and for severe cases medications are available.

3) By social interaction we mean the in-person kind, not social media, which can be mentally toxic to teenagers.

4) The UCSF study is based on "predictive models" that have not been verified by observation:

The study pulled data from 15,000 people in different age cohorts, ranging from 20-89 — divided into older, midlife and young adulthood — and used predictive methods to estimate the average trajectory of depressive symptoms. That trajectory is used to make a “best guess” of how older adults with dementia might have been in early adulthood.

While this methodology isn’t as good as studying someone over a lifetime,[ Dr. Willa] Brenowitz said, it’s the best researchers have now — and should spotlight the need to start observation for dementia risk factors earlier in life.

Predictive models are works-in-progress, as we have seen from much more elaborate climate, epidemiological, and econometric models that have made predictions that proved to be wildly inaccurate.

It's useful that the connection between depression and dementia is being explored. It's also true that the models can be wrong, and even, if true, there is time to take the steps that can break the connection.