Digital Mental Health Interventions: A Global Narrative Review of Effectiveness, Applications, and Future Directions

Digital mental health interventions are becoming an increasingly important part of psychological care, especially as technology continues to shape how people communicate and access support. These tools can help individuals receive mental health support even when distance, stigma, or limited services make traditional therapy difficult to access. This narrative review summarises current evidence on the effectiveness of digital interventions for conditions such as depression, anxiety, sleep problems, stress, and trauma. It also describes common intervention types, including internet-delivered cognitive behavioural therapy (iCBT), mobile mental health apps, teletherapy, self-help programs, and AI-based conversational agents.Research generally shows that guided iCBT and teletherapy can be as effective as in-person treatment for mild to moderate symptoms, while digital CBT for insomnia has some of the strongest clinical support. At the same time, challenges remain, including privacy concerns, high dropout rates, unequal access to technology, and the need for stronger scientific evaluation. The review highlights opportunities to improve digital mental health care, such as better integration with existing health systems, more cultural adaptation, and ethical frameworks for the use of artificial intelligence. With thoughtful development and responsible implementation, digital mental health interventions have the potential to expand access to effective support and improve global mental health outcomes.Keywords: digital mental health, iCBT, mental health apps, teletherapy, artificial intelligence, sleep, anxiety, depression, narrative review