Study finds CBT app Daylight reduces symptoms of anxiety

The study also found that individuals experienced a greater remission in anxiety than those in the control group.
By Laura Lovett
03:12 pm

A new randomized control trial published by the Anxiety and Depression Association of America found that participants using Big Health’s cognitive behavioral therapy app Daylight reduced symptoms of anxiety. 

Researchers also found that participants using the app had a decrease in secondary symptoms such as worry and depressive symptoms. 

“In this study, we found that Daylight helped participants improve their anxiety at rates similar to in-person care,” Dr. Jenna Carl, vice president of clinical development and medical affairs at Big Health, told MobiHealthNews via email.

“This has huge implications for how to increase access to mental health care, because smartphones are so widely owned – in the US they’re owned by about 80% of the population. Given that many people with mental health care difficulties do not get access to any care or only limited care (e.g., only medications or limited psychotherapy appointments), effective mental health programs delivered via smartphone could really extend access and increase people’s options. It’s not possible to address the large unmet need solely with additional mental health care providers because the shortage is too substantial, and of course stigma is still an issue – some people don’t want in-person care.”


Researchers found a significant reduction in participants GAD-7 scores, a tool used to measure anxiety, in the digital CBT group compared to the control group, whose members were on the wait list. At baseline the wait list control had a mean GAD-7 score of 15.6, and the Digital CBT group also had a mean of 15.6. 

At the six-week intervention point the control group reported a mean of a 12.66 GAD-7 score, and the intervention group's was 9.46. The gap was larger at follow-up week 10, where the control group reported 12.15 and the controls was 7.9.

“There was a significant reduction in GAD‐7 anxiety scores in the digital CBT group compared with the waitlist control group at all assessment time points with large between‐group effect size scores at mid‐intervention (d = 0.96), post‐intervention (primary endpoint: d = 1.08), and at follow‐up (d = 1.43),” researchers wrote. 

Researchers also found that participants who used the Daylight app were more likely to experience remission in anxiety than their peers. 

“Improvements were clinically meaningful as 52% of participants in the digital CBT group experienced reliable remission in anxiety symptoms at post‐intervention compared with 27% in the waitlist control,” authors wrote in the study. 

Participants in the control group also reported a decrease in secondary symptoms, such as difficulty sleeping, lower well-being and worry.


The study included a total 256 participants with moderate to severe anxiety. Half of the participants were in the intervention group and the other half were in the wait list control group. 

Participants in the intervention group were able to access the Daylight app on their personal smartphone. An online assessment was given at baseline, then mid-intervention (three weeks in), post-intervention (six weeks in) and follow-up (ten weeks in). 

It is important to note that several of the authors of the paper are employees of Big Health. 


Digital mental health tools have become plentiful. However, research on the tech has often been lacking. 

A 2019 study published in Nature Digital Medicine found that a majority of the apps studied did not provide evidence or peer-reviewed studies to back up their products.  

“[T]he more we conduct research, the more we can contribute to overall understanding of this emerging category,” Carl wrote to MobiHealthNews. “Keep in mind that a dozen randomized controlled trials or RCTs have been completed for our Sleepio product (launched several years ago), so conducting an RCT for Daylight was a natural next step (note that Daylight was launched last year). The RCT is considered the 'gold standard' in clinical trials research. Our desire in our second study for Daylight was to further validate the promising findings of our first study, but with a larger population and a control group, so this study included 256 participants - 128 people who were randomly assigned to Daylight and 128 people randomly assigned to the control group.” 


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