While many people experience symptoms of depression and anxiety at some point in their lifetime, finding a therapist can be a difficult process, and waitlists are long. My Cognition and Affect Research and Education (CARE) lab at McLean Hospital/Harvard Medical School is working on one potential solution to this problem: Smartphone apps. Digital interventions like smartphone apps have the potential to increase access to tools that can be self-administered when and wherever people want. However, most apps in the app store do not have any clinical evidence to support their usefulness. In contrast, we aim to develop and validate digital interventions through rigorous research.
HabitWorks: A Smartphone app for negative thinking habits
HabitWorks is a Smartphone app that is designed to shift negative or unhelpful thinking habits (Beard et al., 2021). Depression and anxiety disorders are characterized by a tendency to jump to negative interpretations of ambiguous or uncertain situations (referred to as a negative interpretation bias). A classic example of interpretation bias from my life happened when I was working as a bank teller in college. On a Friday afternoon, my boss told me she wanted to meet with me on Monday to discuss something, but she didn’t say what. I immediately assumed that I must be in trouble or did something wrong. I spent the entire weekend ruminating about what it could be and as a result felt super anxious. As I entered her office that Monday, my heart was racing. Then, she told me that she wanted to promote me and asked if I would be willing to take on more responsibilities!
How we interpret daily ambiguous situations like these has a huge effect on how we feel and how we respond. In this way, negative interpretation bias is thought to maintain anxiety and depression (Hirsch et al., 2016). Given how many ambiguous situations people encounter on a daily basis, interpretation bias can have a huge impact on how people feel. For these reasons, our best anxiety and depression treatments (such as Cognitive Behavioral Therapy) typically help people to question their distorted thinking.
We developed HabitWorks as a new tool to help interpretation bias in collaboration with people with lived experience of anxiety and depression. Instead of talking through situations in therapy, HabitWorks uses brief, game-like exercises to teach people to make more neutral or positive interpretations of ambiguous situations and to stop jumping to negative interpretations. Through repeated practice, the app helps people gain insight and awareness into their own mental habits and, over time, develop healthier ways of responding to uncertainty. In addition to interpretation bias exercises, the app includes several innovative features designed to increase app engagement, such as a personalization checklist that enables people to select the types of ambiguous situations that are most relevant for them, performance feedback, and level progression.
The app showed promising early results in three small pilot open trials among patients attending intensive psychiatric treatment (Beard et al., 2021), anxious parents (Beard et al., 2022), and Black and Hispanic adults with anxiety and depression (Ferguson et al, 2024). As a next step, we recently conducted our first randomized controlled trial of HabitWorks in a sample of 340 adults across the United States, and results will soon be published in the Journal of Consulting and Clinical Psychology (Silverman et al., in press).
In this new study, participants were randomly assigned to: (1) the HabitWorks condition, in which they were asked to complete interpretation bias exercises in the HabitWorks app 3 times per week for 4 weeks; or (2) a symptom tracking comparison condition, in which they were asked to answer questions about their depression and anxiety symptoms 3 times per week for 4 weeks. We chose a symptom tracking comparison because self-monitoring symptoms can be helpful, and people typically enjoy doing it. Thus, we compared HabitWorks to an active and credible comparison. Here’s what we found:
People in both HabitWorks and the Symptom Tracking conditions showed significant improvements in depression and anxiety symptoms after 4 weeks. These improvements were not significantly different between conditions.
People who used HabitWorks rated it highly on measures of app usability and acceptability. They also had strong app adherence: 77.8 percent were still using HabitWorks in the fourth week, and 43.7 percent had perfect adherence (defined as completing 3 HabitWorks exercises per week for 4 weeks).
Compared to people in the Symptom Tracking condition, people who used HabitWorks showed significantly greater improvements in interpretation bias, functioning, and global severity of symptoms after 4 weeks.
One of the most striking findings was that most people used HabitWorks for the 4 full weeks of the study. A big challenge in the field of digital mental health interventions is that people typically stop using them before any benefit can occur. Although this study cannot identify why people continued to use HabitWorks, we expect it may be due to the substantial amount of input we obtained from people with lived experience to create a simple, relevant, and engaging tool.
These promising results suggest that HabitWorks is an engaging and satisfactory Smartphone app that is effective for improving interpretation bias, functioning, and global severity. Future research with even more people is needed to help understand who stands to benefit the most from using HabitWorks and how long these effects may last. Digital tools, such as HabitWorks, with strong evidence supporting them, have the potential to help address the huge treatment needs across the US.
Dr. Alexandra Silverman contributed to this article. Dr. Silverman is a clinical psychologist in the Cognition and Affect Research and Education (CARE) Lab at McLean Hospital and an Instructor in the Department of Psychiatry at Harvard Medical School.