Birth order—a unique index of both neurodevelopmental and/or psychosocial factors in the pathogenesis of psychiatric disorder—remains largely unexplored in violent schizophrenia. We examined whether murderers with schizophrenia would demonstrate birth order anomalies, distinguishing them from both nonviolent schizophrenia patients and murderers without schizophrenia. Self-report birth order, psychosocial history data (i.e., maternal birth age, family size, parental criminality, parental SES), and structural magnetic resonance imaging data were collected from normal controls, nonviolent schizophrenia patients, murderers with schizophrenia, murderers without schizophrenia, and murderers with psychiatric conditions other than schizophrenia at a brain hospital in Nanjing, China. Results indicated that murderers with schizophrenia were characterized by significantly increased (i.e., later) birth order compared with both nonviolent schizophrenia patients and murderers without schizophrenia. Additionally, birth order was negatively correlated with gray matter volume in key frontal subregions for schizophrenic murderers, and was negatively correlated with parental SES. Findings may suggest biological, psychosocial, or interactional trajectories which may lead to a homicidally violent outcome in schizophrenia.
*Department of Criminal Justice, California State University, Long Beach, CA; †Laboratory of Neuro Imaging, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA; ‡Departments of Criminology, Psychiatry, and Psychology, University of Pennsylvania, Philadelphia, PA; §Department of Forensic Psychiatry, Nanjing Brain Hospital, Nanjing Medical University, Nanjing, China; ¶School of Nursing, University of Pennsylvania, Philadelphia, PA; and ∥School of Medicine, University of Pennsylvania, Philadelphia, PA.
Supported by Award Number 5F31MH074167-03 from the National Institute of Mental Health (to R.A.S.) and a Zumberge Interdisciplinary Research Grant (to A.R.).
The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of Mental Health or the National Institutes of Health.
Send reprint requests to Robert A. Schug, PhD, Department of Criminal Justice, California State University, Long Beach, 1250 Bellflower Blvd, Long Beach, CA, 90840. E-mail: firstname.lastname@example.org.