BackgroundAccess to traditional mental health services in Canada remains limited, prompting exploration into digital alternatives. The Government of Ontario initiated access to two internet-based cognitive behavioral therapy (iCBT) programs, LifeWorks AbilitiCBT and MindBeacon TAiCBT, for adults with mental health issues.MethodsAn uncontrolled observational study utilizing secondary retrospective program data was conducted to evaluate the reach, uptake, and psychological symptom changes among participants engaging with either iCBT program.ResultsBetween May 2020 and September 2021, 56,769 individuals enrolled in LifeWorks AbilitiCBT, and 73,356 in MindBeacon TAiCBT. However, substantial exclusions were made: 56% of LifeWorks participants and 68% of MindBeacon participants were ineligible or failed to initiate treatment. Consequently, 25,154 LifeWorks participants and 23,795 MindBeacon participants were included in the analysis. Of these, 22% of LifeWorks and 26% of MindBeacon participants completed over 75% of iCBT treatment. On average, LifeWorks participants received 13 ± SD 7.1 therapist messages and sent 5 ± SD 10.3 messages, while MindBeacon participants received 25 ± SD 20.7 therapist messages and sent 13 ± SD 16.4 messages. LifeWorks included synchronous therapist contact averaging 1.4 ± SD 1.9 h per participant, while MindBeacon was purely asynchronous. Baseline severity of anxiety (37%) and depression symptoms (22%) was higher for LifeWorks participants compared to MindBeacon participants (24% and 10%, respectively). Clinically significant changes in anxiety and depression scores were observed: 22% of LifeWorks and 31% of MindBeacon participants exhibited reliable recovery in PHQ-9 scores, while 26% of LifeWorks and 25% of MindBeacon participants demonstrated reliable recovery in GAD-7 scores.ConclusionIn conclusion, iCBT programs show promise for engaged participants with varying levels of severity in anxiety and depression symptoms. Future iterations of iCBT should consider adopting a broad entry criterion to iCBT programming to increase accessibility, especially for those with severe symptoms, alongside integrated intake care pathways, and potential payment structure adjustments for iCBT service providers. Taken all together, these factors could temper high dropout rates post-intake assessment. This evaluation underscores the potential and value of digital mental health interventions for individuals with mild to severe anxiety or depression symptoms, emphasizing the importance of addressing participant dropout.