Wearables may offer clues to psychiatric diagnoses

Alex Eben Meyer

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A study by a Yale-led research team has shown that more accurate diagnosis of attention-deficit/hyperactivity disorder (ADHD) and other mental health conditions may be on the horizon, thanks to wearable sensors such as smartwatches. The study was published in the journal Cell.

ADHD, characterized by difficulty focusing, restlessness, and impulsive behavior, is the most commonly diagnosed behavioral disorder in children; it can lead to disruptions in learning and daily functioning. Early, accurate diagnosis and intervention can be critical in minimizing its impact. The problem, notes co–senior author Mark Gerstein, the Albert L. Williams Professor of Biomedical Informatics, is that “ADHD has traditionally been diagnosed symptomatically, and there is an element of subjectivity to categorizing human behavior. We wanted to see if wearable devices could increase diagnostic precision.”

The study analyzed clinical, wearable, and genetic data from 11,878 US adolescents (ages 9–14) recruited by the NIH Adolescent Brain Cognitive Development Consortium project. Information collected included measurements of heart rate, calorie expenditure, activity intensity, steps, and sleep intensity.

The researchers determined that correctly processed smartwatch data could be used as a “digital phenotype.” (Phenotype is the observable expression—physical characteristics, behaviors—of someone’s genotype, which is each person’s unique DNA sequence and their environment.) “We found,” says Gerstein, “that from the sensor readings we could quite accurately determine if someone has ADHD.”

The researchers used the data to train AI models to identify two psychiatric disorders. They further determined which measurements were most useful in characterizing them. Heart rate was the most important predictor for ADHD, while sleep quality and stage were more useful for identifying anxiety. Based on the patterns across the wearable features, the researchers were able to pinpoint genes and genetic variants associated with ADHD.

Gerstein notes the significance of making the connection to genotype. “We found that the smartwatch measurements can better relate disorders to genetics than just correlating them directly with clinical diagnoses,” he says. “Finding more genetic variants and genes related to the disorders could uncover molecular mechanisms and give us pathways to new treatments.”