A severe, chronic disability which is attributable to a mental or physical impairment or combination of mental and physical impairments; is likely to continue indefinitely; results in substantial functional limitations in three or more of the following areas of major life activity: self-care, receptive and expressive language, learning, mobility, self-direction, capacity of independent living, economic self-sufficiency; and reflects the person’s need for a combination and sequence of special, interdisciplinary or generic care treatments or services which are of lifelong or extended duration and are individually planned and coordinated. (World Health Organization)