This Mentored Patient-Oriented Research Career Development Award (K23) focuses on the psychopharmacologic treatment of autism and related pervasive developmental disorders (PDDs). Autism and other PDDs are increasingly being diagnosed and are the source of serious lifelong disability. Despite investigations into the pharmacologic treatment of autism, no drugs have been proven to consistently improve the core symptoms of the disorder, namely social and communication impairment. The principal investigator's long-term career goal is to determine the best and most effective pharmacologic treatments for autism and related disorders. The principal investigator's specific aims are to expand his knowledge of psychopharmacology and clinical research by conducting controlled treatment studies in autism. After this training, the principal investigator will have the necessary skills to launch his career as an independent investigator in this field. To accomplish these goals, the principal investigator will work closely with his mentor, Christopher J. McDougle, M.D., an expert in the pharmacotherapy of these disorders, in implementing the research plan. Specifically, the research plan includes a double-blind, placebo-controlled study of D-cycloserine for the treatment of social withdrawal associated with autism. Pilot data has suggested that D-cycloserine, a drug that affects the N-methyI-D-aspartate (NMDA) subtype of glutamate receptor, has efficacy for the symptom of social withdrawal in autism. This project proposes to study the efficacy and safety of D-cycloserine in 60 children and adolescents with autism. Also integral to this award will be dedicated time focused on didactic courses in the following areas: advanced psychopharmacologic principles, clinical research methodology, biostatistics, research ethics, epidemiology, writing and presentation skills, and grant preparation. This curriculum will lead to a Master of Science in Clinical Research degree offered by Indiana University. Augmenting this coursework, will be additional consultation with experts in the field, attendance and presentations at national scientific meetings, training in behavioral measures necessary for clinical trials in autism, and additional coursework and seminars in neuropsychopharmacology and preclinical research. Towards the later years of the award, the candidate will have performed additional studies and applied for independent research funding.