Few interventions are available for adults with ASD; as a consequence, many verbal adults with ASD experience substantial lifetime disability. This study will adapt and carry out preliminarily testing of the efficacy of Cognitive Enhancement Therapy (CET) for young transitional age high functioning adults with ASD to improve adaptive functioning and adult life achievement in this population. CET is a neurodevelopmentally-based, social-cognitive, and neurocognitive rehabilitation program originally developed for schizophrenia that has demonstrated significant improvements in cognition and important functional outcomes. Many of the social, communication, and cognitive impairments experienced by persons with ASD are also shared by individuals with schizophrenia. These impairments are directly targeted by CET, suggesting that CET may confer substantial benefits to verbal individuals with ASD who often do poorly as adults and for whom few interventions exist. In the first phase of this project (covered by this proposal), adaptations to the CET treatment reflecting the uniqueness of autism will be made through the development of a supplement to the existing CET treatment manual. Clinical experts in autism and schizophrenia will collaborate to adapt CET, and then conduct an uncontrolled pilot study of these adaptations with 12 young adults with ASD to demonstrate feasibility, identify the need for additional adaptations, and provide an initial evaluation of the potential social-emotional and cognitive effects of the approach. In the second phase, a small-scale randomized trial with 55 young adults with ASD will be conducted to obtain initial efficacy data on a broad range of cognitive, functional, and neurobiological outcomes to support the feasibility of a larger and more definitive trial of CET for ASD. The combined phases will result in the completion of the first rigorous clinical trial of a proven cognitive rehabilitation approach with verbal adults with ASD. If successful, this project will result in a major step forward in available interventions for adults with ASD.