What distinguishes autism from other pervasive developmental disorders?

Autism is characterized by developmental differences that typically manifest before the age of 30 months. This early onset is crucial because it distinguishes autism from other conditions, allowing for early diagnosis and intervention. Research indicates that signs of autism can often be noticeable in the early months of life, such as differences in social interaction, communication skills, and behavior patterns.

When considering the other options, presenting symptoms only after 30 months does not accurately define autism, as this would imply a delayed onset that is not typical of the disorder. Additionally, stating that autism is less severe than other conditions is also a misconception; severity can vary widely within the autism spectrum itself. Furthermore, the notion that autism requires no special interventions is incorrect, as individuals with autism often benefit significantly from tailored therapies and support services to improve social, communication, and everyday functioning skills.