Autism typically develops early in childhood, with signs often appearing between six months and three years of age. While autism is usually diagnosed between the ages of 5 and 6, it can be diagnosed as early as 12 months, and some early signs can be seen as young as six months. Key developmental milestones related to social communication and behavior usually reveal autism symptoms around 12 to 18 months, though some children may not show signs until 2 years or later. Importantly, autism is a neurodevelopmental disorder present from early brain development, so it does not develop later in adulthood, but it can be diagnosed at any age if previously unrecognized.
Early Signs of Autism
- Problems with eye contact, responding to name, and joint attention
- Fewer social communication behaviors such as pointing and gesturing
- Restrictive, repetitive behaviors like hand flapping or intense interests
- Possible regression in skills between 1 and 2 years old
Diagnosis Age Range
- Earliest diagnosis possible at 12 months
- Most diagnoses between 3 and 10 years old, average around 5 years
- Some signs may be subtle and diagnosed later, even in adulthood, but the condition is present from childhood
Autism is thus recognized as developing during early childhood brain development, with symptoms manifesting in infancy or toddlerhood, though clinical recognition and diagnosis timing can vary widely. Early diagnosis enables important early intervention to aid communication and development.
