The rapid growth of generative artificial intelligence in digital mental health interventions offers significant opportunities to improve mental healthcare access while creating new regulatory challenges. This paper responds to recent U.S. Food and Drug Administration initiatives, including the September 2025 Digital Health Advisory Committee meeting, by proposing comprehensive regulatory frameworks for generative AI digital mental health devices. We analyze the current regulatory landscape, identifying gaps in U.S., international, and state-level governance structures. Through quantitative foundations including mathematical models for risk assessment, objective functions for regulatory optimization, and the 4 lens framework for significant change evaluation, we establish evidence-based approaches for device assessment. We present architectural diagrams covering lifecycle regulatory pathways, multi-layered safety architectures, risk-tiered assurance frameworks, and multi-stakeholder governance models. Drawing from clinical evidence showing both potential benefits and significant risks, we advocate for balanced regulatory approaches. Our framework integrates technical safeguards, ethical considerations based on care ethics, transparency requirements, and post-market monitoring systems. We provide implementation roadmaps, quantitative algorithms for regulatory decisions, and cost-benefit analyses to support practical deployment. The paper concludes with specific recommendations for risk-based classification, adaptive oversight systems, international coordination, and enhanced professional involvement to ensure these technologies provide therapeutic benefits while maintaining strong patient safety standards throughout their lifecycle. This is a review and synthesis paper that summarizes and organizes existing proposals, frameworks, and discussions from current literature; the author does not claim original authorship of the regulatory frameworks presented but rather provides a systematic analysis of the current discourse.