Section 18. Subject to approval by the secretary of health and human services, the commissioner may enter into interagency agreements with the commissioner of mental health or the office of Medicaid for the coordinated regulation of or for the coordinated or joint management of certain services that are required or that shall be provided by the department of developmental services and the department of mental health or the office of Medicaid. Such an agreement may be entered into where it is determined by the commissioners of the departments and the director of Medicaid that the services require coordinated regulation to ensure development of substantially similar standards consistent with certain shared needs of persons with a mental illness and persons with an intellectual or developmental disability or persons enrolled in the commonwealth's money follows the person demonstration waiver or related waivers or that the services will be more efficiently and effectively provided by a single, unified management system than by 2 separate management systems. These services may include, without limitation, transportation, laundry, data processing, certain services to mixed populations of persons with a mental illness and persons with an intellectual or developmental disability with common needs for care and treatment or to persons who have been diagnosed as having both an intellectual or developmental disability and a mental illness, research activities, program monitoring and services provided to persons enrolled in the commonwealth's money follows the person demonstration waiver or related waivers. Coordinated regulation of these services may include, without limitation, issues such as restraint, charges for care, investigations and case management. Under these agreements, the department of developmental services may assume responsibility for the provision of these services to the department of mental health or the office of Medicaid. These agreements may delegate responsibility to the department of mental health to provide those services to the department of developmental services. These agreements may provide for the expenditure of appropriated funds consistent with the joint management service systems and may further provide for assignment of certain staff to the joint management service system. These agreements shall not conflict with the department of developmental services' primary responsibility for persons with an intellectual disability or a developmental disability regardless of whether those persons also have a mental illness or are enrolled in the commonwealth's money follows the person demonstration waiver or related waivers.