Section 1 of Chapter 123B of the General Laws is hereby amended by striking out the definition of “Person with an intellectual disability” as amended by Section 41 of Chapter 239 of the acts of 2010, and inserting in place thereof the following:-

“Person with an intellectual disability”, a person who has an intellectual disability, consistent with the 11th Edition (2010) definition of the American Association on Intellectual  and Developmental Disabilities, characterized by significant limitations in both intellectual functioning and adaptive behavior as expressed in conceptual, social and practical adaptive skills.  This disability begins before age 18.  The following five assumptions are essential to the application of this definition: (1) limitations in present functioning must be considered within the context of community environments typical of the individual’s age, peers, and culture; (2) valid assessment considers cultural and linguistic diversity as well as differences in communication, sensory, motor and behavioral factors; (3) within an individual, limitations often coexist with strengths; (4) an important purpose of describing limitations is to develop a profile of needed supports; and (5) with appropriate personalized supports over a sustained period, the life functioning of the person with an intellectual disability generally will improve.   A person who has an intellectual disability may be considered to be mentally ill, provided further, that no person with an intellectual disability shall be considered to be mentally ill solely by reason of the person’s intellectual disability.”