Mark F. Lenzenweger, PhD, is a Senior Research Fellow at the Personality Disorders Institute, Adjunct Professor of Psychology in Psychiatry, Weill Cornell Medical College, and Distinguished Professor, Department of Psychology, The State University of New York at Binghamton. He has been on the professorial faculties at Cornell and Harvard as well. Affiliated with Weill Cornell Medical College since 1984, he serves as methodologist and statistical analyst for the ongoing psychotherapy studies of borderline personality disorder at the Personality Disorders Institute (Principal Investigator: John Clarkin). He has studied the neurocognitive nature of borderline personality disorder and he has developed a theoretical model linking neurobiology, neurobehavioral systems, personality, and personality disorders. Lenzenweger is the Principal Investigator of the NIMH-funded Longitudinal Study of Personality Disorders and he is a NARSAD Distinguished Investigator Award recipient for his scientific studies of endophenotypes in schizotypy and schizophrenia. In addition to his scientific work, he maintains a private practice focused on transference-focused psychotherapy of personality pathology.