Is it possible to develop autism after birth?

Autism does not develop later in life in the way an illness or injury does. It is a neurodevelopmental condition that is present from birth, shaped by genetics and early brain development.

That said, autism is not always recognized at birth or in early infancy. Many children show subtle signs that become more noticeable as they grow, especially when social, communication, and behavioral demands increase. In some cases, a child may appear to develop typically at first and then lose certain skills, which is known as developmental regression. Even in these cases, autism was already present but became more apparent over time.

In adults, a “late diagnosis” can happen when lifelong traits were previously misunderstood, masked, or attributed to other factors. This can create the impression that autism developed later, when in reality it was always there.

So, autism cannot be acquired after birth, but it can be identified or diagnosed later in life