The Developmental Services Act defines a developmental disability as "a condition of mental impairment, present or occurring during a person's formative years, that is associated with limitations in adaptive behaviour."
A developmental disability is a life-long condition and can be accompanied by other physical conditions. This disability varies greatly among individuals. A person with a developmental disability may have limitations in intellectual ability and difficulties in many common daily activities or life skills, such as personal hygiene and dressing, communication, learning, mobility, ability to live independently, and economic self-sufficiency.
Some people have what is referred to as a dual diagnosis. This term is used to describe someone who is diagnosed with both a developmental disability and a mental illness.