People can be diagnosed as autistic at any age. Some people will be diagnosed as young children, because their autistic characteristics are more obvious from a younger age. Others may be diagnosed later in life, and some not at all. Some autistic people may choose to self-identify and not feel the need for a formal diagnosis.
Our understanding of autism, and what it can look like in different people, is constantly improving. As a result, many autistic people whose autism was missed when they were younger, are now being identified. This often happens after a child or relative is diagnosed and people learn more about autism or identify with various characteristics.
People come to be diagnosed for many different reasons, but we know that it is extremely important for people to know they are autistic and understand what this means to them.
A diagnostic assessment involves meeting with several different specialists and undergoing tests and observations; it is an in-depth process, not a tick-box exercise.
To be diagnosed as autistic, there must be evidence of differences from a young age in certain areas – social communication and interaction, self-stimulatory behaviours, activities and interests and sensory differences. There are various tools that diagnosticians may use during an assessment.
You can find more information on diagnostic tools here.