The science

Internet-based cognitive and behavioral therapy

What iCBT is, why it's the most credible form of digital mental health care, and why, after 25 years, it's due for reinvention.

What iCBT is

Cognitive and behavioral therapy (CBT) is the most extensively studied approach in clinical psychology. iCBT delivers its skills and strategies through structured online programs, typically 6 to 12 modules, each presenting educational material or teaching a therapeutic technique.

Programs are either fully self-guided or completed with limited support from a therapist. Because they don't require weekly appointments, they cost far less than one-on-one therapy and can reach people who would otherwise get no support at all.

The research base is substantial

iCBT stands apart from the mental health apps on the app stores, already estimated at 10,000 in 2017 (Torous & Roberts, 2017). Real-world use of those apps is close to negligible (Baumel et al., 2019), and trials of apps delivering psychological interventions find only small improvements (Goldberg et al., 2022). iCBT programs are different in kind: developed with clinicians, evaluated in peer-reviewed trials spanning two decades, and showing moderate to high effectiveness across a wide range of difficulties (Taylor et al., 2021). The findings on this page describe that published literature, not the platform THEOR-E is building.

Browse established iCBT programs and their evidence

Where it stalled

The delivery model has barely changed since the early 2000s: report a primary diagnosis, receive the matching fixed program. Three problems follow from that design.

One label, one program

Programs are built for a single diagnosis. But having more than one difficulty at once is the norm rather than the exception (McGrath et al., 2020), and the secondary ones generally go unaddressed.

Passive by design

Most programs are chapters to read and videos to watch. Little interactivity, little practice, and little or no meaningful use of AI.

People disengage

When Ontario funded free access to two of Canada's largest iCBT programs during COVID-19, 48,949 adults enrolled. Only 22–26% completed more than three-quarters of their program, and anxiety and depression symptoms fell by just 13–17% on average (Khan et al., 2024).

The companies behind today's iCBT haven't fixed this. Employee-assistance providers treat iCBT as one product in a broad portfolio; dedicated iCBT companies have more focus but still ship the same model that was studied twenty years ago.

Sources

  • Baumel, A., Muench, F., Edan, S., & Kane, J. M. (2019). Objective user engagement with mental health apps: Systematic search and panel-based usage analysis. Journal of Medical Internet Research, 21(9), Article e14567. https://doi.org/10.2196/14567
  • Goldberg, S. B., Lam, S. U., Simonsson, O., Torous, J., & Sun, S. (2022). Mobile phone-based interventions for mental health: A systematic meta-review of 14 meta-analyses of randomized controlled trials. PLOS Digital Health, 1(1), Article e0000002. https://doi.org/10.1371/journal.pdig.0000002
  • Khan, B. N., et al. (2024). Reach, uptake, and psychological outcomes of two publicly funded internet-based cognitive behavioural therapy programs in Ontario, Canada: An observational study. International Journal of Mental Health Systems, 18(1), Article 34. https://doi.org/10.1186/s13033-024-00651-9
  • McGrath, J. J., et al. (2020). Comorbidity within mental disorders: A comprehensive analysis based on 145 990 survey respondents from 27 countries. Epidemiology and Psychiatric Sciences, 29, Article e153. https://doi.org/10.1017/S2045796020000633
  • Taylor, C. B., Graham, A. K., Flatt, R. E., Waldherr, K., & Fitzsimmons-Craft, E. E. (2021). Current state of scientific evidence on internet-based interventions for the treatment of depression, anxiety, eating disorders and substance abuse: An overview of systematic reviews and meta-analyses. European Journal of Public Health, 31(Suppl. 1), i3–i10. https://doi.org/10.1093/eurpub/ckz208
  • Torous, J., & Roberts, L. W. (2017). Needed innovation in digital health and smartphone applications for mental health: Transparency and trust. JAMA Psychiatry, 74(5), 437–438. https://doi.org/10.1001/jamapsychiatry.2017.0262

What comes next

We are rebuilding the delivery model rather than adding another fixed program to the pile.

For organizationsHow it works