Measuring mental health with biometrics: A questionable pursuit

One of the difficulties of psychology and psychiatry is assessing mental health. I prefer the term “assessment” to “measurement” because measurement subtly implies that mental health is a singular thing you can quantify.

What is mental health anyway? Here’s a definition:

emotional, behavioral, and social maturity or normality; the absence of a mental or behavioral disorder; a state of psychological well-being in which one has achieved a satisfactory integration of one’s instinctual drives acceptable to both oneself and one’s social milieu; an appropriate balance of love, work, and leisure pursuits.

Phew! That sure covers a lot. You have to look at:

  • Emotional, behavioral, and social dimensions
  • Presence or absence of disorders
  • Integration of instinctual drives (for food, sex, love…)
  • Adaptation to one’s social milieu
  • And a balance of love, work, and leisure

A company called Medibio has launched a personal mental health measurement app for the Apple Watch, that they say provides objective measurement of mental health:

With the Medibio app, Apple Watch users will be able to capture and process specific biometric features that reflect the performance of the body’s autonomic nervous system (ANS) to create an objective view of their mental health.

This seems far-fetched. Since mental health includes so much beyond what’s detectable physiologically how could this possibly work? The app store page for this app shows that it provides a “mental index summary” which must be their rating of overall mental health. The page mentions that it determines “stress and other mental health conditions.”

Their website suggests that they analyze circadian heart rhythm especially during sleep since “distinctly different patterns are evident during sleep when confounding influences on heart rate are minimal.”

But evidence that heart rate variability will help identify mental health issues is limited. For example, a 2008 article in the Archives of General Psychiatry reported that while depression is associated with significantly lowered heart rate variability, this association “appears to be mainly driven by the effect of antidepressants.” That confounder will still be present during sleep of course.

I’m sure there’s plenty more research that’s been done in this area, and granted, I’m no expert on heart rate variability and mood.

Medibio also offers an app that does a more traditional mental health assessment, asking the user to rate agreement with statements like “I was worried about situations in which I might panic and make a fool of myself.” That sounds like social anxiety, no? Medibio’s Inform app rates you on depression, anxiety, and stress levels. That hardly exhausts mental health, though no one would dispute that depression and anxiety are two of the most serious ways in which mental health can be compromised.

Medibio’s app is just one of many mental health apps. I’ll be taking a look at others in the near future.