The metaverse, defined as a collective virtual shared space created by the convergence of augmented reality (AR), virtual reality (VR), and the Internet, offers new opportunities for mental healthcare by delivering immersive and engaging digital therapies. This study examines the current landscape of metaverse-based mental healthcare applications, analyzing their effectiveness and potential risks. Using a systematic literature review (SLR) and case study research, four digital therapeutic applications-NightWare, Freespira, EndeavorRx, and Sleepio-were evaluated for their ability to address conditions such as PTSD, anxiety, and ADHD. The results indicate that metaverse-based therapies can provide significant benefits, with clinical validation supporting their effectiveness. However, concerns around user privacy, accessibility, and long-term efficacy remain challenges. Overall, metaverse-based digital therapies represent a promising shift in mental healthcare, offering innovative, personalized, and scalable solutions. Further research is needed to address ethical issues, improve accessibility, and confirm the long-term impact of these interventions.