A Randomized Clinical Trial for Toddlers With ASD

Inclusion Criteria: * Participants must be 22 to 33 months old * Children must meet criteria for ASD or autism on the ADOS plus receive a clinical judgment of PDD-NOS or autism by the study team * Children must have an age equivalent of 8 months or greater for non-verbal ability based on the Mullen Visual Reception and Fine Motor scales * Parents must agree to participate in the study and commit to having their child participate in the intervention to which they are randomized for 6 months * The parent (or other primary caregiver, such as grandparent) in the Parent-Mediated condition must agree to attend the training sessions three times per month * Parents must be between the ages of 16 and 50 years old * Families who qualify for medical assistance and/or have racial/ethnic minority backgrounds will be prioritized for recruitment and participation in this study. On the TSI, we will ask participants if they qualify for medical assistance or if they are of a racial minority or have a first degree relative of a racial minority. Families who do not fit these criteria will be notified that they may be eligible to participate if additional space is available. * It is not required that English be their primary language, but they must be fluent in English (or if the child is nonverbal he/she must hear English most of the time at home) Exclusion Criteria: * Head injury prior to enrollment in the study * Major hearing or visual impairment after correction * Non-febrile seizures * PKU (Phenylketonuria) * Congenital Rubella (German measles) * Neurofibromatosis * Tuberous Sclerosis * Fragile X * A fall resulting in a loss of consciousness or other severe head injury * Velo-Cardio Facial Syndrome * Any other known genetic syndrome * No foster children may participate * The child must not be adopted