The growing acceptance of cannabis for mental health conditions may be premature, as mounting evidence suggests therapeutic claims lack rigorous scientific support. This matters for millions of adults considering cannabis as an alternative to conventional treatments for anxiety, depression, and PTSD. The comprehensive systematic review examined existing research across multiple mental health conditions, analyzing studies that met strict methodological criteria. Investigators found insufficient high-quality evidence supporting cannabis efficacy for treating depression, anxiety disorders, or post-traumatic stress disorder. Most available studies suffered from small sample sizes, short duration, or inadequate control groups. The analysis revealed significant gaps between popular perception and clinical reality regarding cannabis therapeutic potential. This finding challenges the narrative that cannabis represents a viable mental health intervention, particularly given its widespread adoption in states with medical marijuana programs. The evidence gap becomes more concerning when considering potential risks including dependency, cognitive effects, and interactions with existing medications. From a broader research perspective, this review highlights the premature medicalization of cannabis before adequate safety and efficacy data emerged. While some individual compounds like CBD show promise in controlled settings, whole-plant cannabis products lack the rigorous testing required for medical recommendations. For health-conscious adults, this analysis suggests approaching cannabis-based mental health treatments with significant caution until more definitive clinical trial data becomes available.