The progressive increase in mental health disorders diagnosis demands proactive and holistic health promotion, as well as personalized symptom treatment. Personalized and holistic health care plans must be appropriate for the individual and integrate the biopsychosocial model. Previous work demonstrates promising capabilities with large language models. However, single-agent architectures generally lack the depth of reasoning required to generate comprehensive plans that respect ethics, privacy, and safety in healthcare. This paper proposes a large language model-based multi-agent system designed to generate personalized, holistic, and evidence-based health and care plans that encompass the mental health domain. An agent-based workflow was developed using the AutoGen framework. The architecture consists of four specialized agents. A dataset of 40 simulated clinical cases was used. The results demonstrate the proposed system's ability to generate comprehensive, holistic clinical and lifestyle plans arising from interactions among multidisciplinary agents. Demonstrating that this type of multi-agent architecture could become a useful tool to support healthcare professionals.