This study evaluates a structured, evidence-based digital program for mild, moderate, and severe anxiety that combines an AI-driven conversational agent with human clinical oversight and user support. The program was designed to maximize engagement and effectiveness by using a structured, evidence-based approach drawing from traditional Cognitive Behavioral Therapy (CBT) and third-wave approaches like Acceptance and Commitment Therapy (ACT). The study aimed to measure engagement, clinical effectiveness, acceptability, and safety of the digital intervention compared to external comparator groups. **Methods:** - **Participants:** 299 participants were given the digital intervention to use for up to 9 weeks. - **Endpoints:** Effectiveness, engagement, acceptability, and safety were collected before, during, and after the intervention, and at one-month follow-up. - **Comparator Groups:** Propensity-matched real-world patient groups included a waiting control, face-to-face CBT, and typed-CBT. **Results:** - Participants used the program for a median of 6 hours over 53 days. - There was a large clinically meaningful reduction in anxiety symptoms for the intervention group, which was statistically superior to the waiting control and non-inferior to human-delivered care. - The intervention achieved comparable reduction in anxiety symptoms to human-delivered care while significantly reducing clinician time by up to 8 times. **Conclusions:** The study demonstrates that combining AI and human support in a digital intervention can achieve clinical outcomes comparable to human-delivered care, highlighting the potential of technology to scale effective mental healthcare, address unmet needs, and impact quality of life and economic burden globally.This study evaluates a structured, evidence-based digital program for mild, moderate, and severe anxiety that combines an AI-driven conversational agent with human clinical oversight and user support. The program was designed to maximize engagement and effectiveness by using a structured, evidence-based approach drawing from traditional Cognitive Behavioral Therapy (CBT) and third-wave approaches like Acceptance and Commitment Therapy (ACT). The study aimed to measure engagement, clinical effectiveness, acceptability, and safety of the digital intervention compared to external comparator groups. **Methods:** - **Participants:** 299 participants were given the digital intervention to use for up to 9 weeks. - **Endpoints:** Effectiveness, engagement, acceptability, and safety were collected before, during, and after the intervention, and at one-month follow-up. - **Comparator Groups:** Propensity-matched real-world patient groups included a waiting control, face-to-face CBT, and typed-CBT. **Results:** - Participants used the program for a median of 6 hours over 53 days. - There was a large clinically meaningful reduction in anxiety symptoms for the intervention group, which was statistically superior to the waiting control and non-inferior to human-delivered care. - The intervention achieved comparable reduction in anxiety symptoms to human-delivered care while significantly reducing clinician time by up to 8 times. **Conclusions:** The study demonstrates that combining AI and human support in a digital intervention can achieve clinical outcomes comparable to human-delivered care, highlighting the potential of technology to scale effective mental healthcare, address unmet needs, and impact quality of life and economic burden globally.