The state of New York and its local governments have a responsibility for the prevention and early detection of mental illness and for the comprehensively planned care, treatment and rehabilitation of their mentally ill citizens. Therefore, it shall be the policy of the state to conduct research and to develop programs which further prevention and early detection of mental illness; to develop a comprehensive, integrated system of treatment and rehabilitative services for the mentally ill. Such a system should include, whenever possible, the provision of necessary treatment services to people in their home communities; it should assure the adequacy and appropriateness of residential arrangements for people in need of service; and it should rely upon improved programs of institutional care only when necessary and appropriate. Further, such a system should recognize the important therapeutic roles of all disciplines which may contribute to the care or treatment of the mentally ill, such as psychology, social work, psychiatric nursing, special education and other disciplines in the field of mental illness, as well as psychiatry and should establish accountability for implementation of the policies of the state with regard to the care and rehabilitation of the mentally ill. To facilitate the implementation of these policies and to further advance the interests of the mentally ill and their families, a new autonomous agency to be known as the office of mental health has been established by this article. The office and its commissioner shall plan and work with local governments, voluntary agencies and all providers and consumers of mental health services in order to develop an effective, integrated, comprehensive system for the delivery of all services to the mentally ill and to create financing procedures and mechanisms to support such a system of services to ensure that mentally ill persons in need of services receive appropriate care, treatment and rehabilitation close to their families and communities. In carrying out these responsibilities, the office and its commissioner shall make full use of existing services in the community including those provided by voluntary organizations.