This is an application for a Mentored Clinical Scientist Award (K08) to facilitate the candidate's transition from a career in infectious disease as a teacher, clinician, researcher and administrator, to a career as an independent researcher in pediatric psychopharmacology. Although the advent of new exciting therapies for the treatment of mental disorders has opened a new era in psychopharmacology, these advancements have not been adequately extended to the benefit of children and adolescents. Because of the limited pharmacokinetic(PK) information, child psychiatrists are forced to prescribe a new generation of psychotropic drugs to children using dosing regimens extrapolated from adults. This approach not only unscientific but may lead to either subtherapeutic doses and poor response or toxic doses and adverse effects resulting from the significant influence of growth and maturation on the pharmacokinetic and pharmacodynamic(PD) behavior of medications. Although there is little doubt that developmental PK and PD research in pediatric psychopharmacology is of critical importance to the advancement of the field, the rate limiting steps for such advancements are the availability of trained experts and appropriate methodology. The candidate's career goal is to develop an independent research program focused on improving the safety and efficacy of drug regimens for children and adolescents with severe disorders by systematically evaluating psychotropic medications using population PK and PD research approaches. The overarching aims of this application are threefold, 1) to train an expert in pharmacokinetic and pharmacodynamic research methods; 2) characterize the pharmacokinetics and pharmacodynamics of three psychotropic drugs; 3) to evaluate the applicability of population pharmacokinetic and pharmacodynamic methods to psychotropic drug research in children and adolescents. The program is designed to build on the candidate's foundation of knowledge and skills to make the transition to pediatric psychopharmacology. The areas include: pediatric growth and development, pediatric psychopathology and psychopharmacology, and research methods(pharmacokinetics, pharmacodynamics, pharmacogenetics, metabolism, epidemiology, pharmacoepidemiology, and advanced statistics). The proposed study, based at the Massachusetts General Hospital will complement a program of training and supervised research with experts in the area of psychopharmacology, PK and PD research. Dr. Joseph Biederman, and Dr. Joseph M. Scavone, Pharm. D (co-mentor). Through coursework at the Harvard School of Public Health and tutorials with consultants including Dr. Ross Baldessarini, Dr. Ene Ette, Dr. C.Lindsay DeVane, Mr. Harold DeMonace, Dr. Gregory Keams, Dr. Roger Jelllife, Dr. Stephen Faraone and Dr. James Flood., The Mentored Clinical Scientist Development Award will allow the Candidate to focus her time and energy necessary to pursue her pdmary goal, a career of independent research in pediatric psychopharmacology.