Prenatal origins of hospitalization for personality disorders: The Helsinki Birth Cohort Study Marius Lahti a, ⁎, Katri Räikkönen a , Kristian Wahlbeck b,c , Kati Heinonen a , Tom Forsén b,d,e , Eero Kajantie b,f , Anu-Katriina Pesonen a,f , Clive Osmond g , David J.P. Barker h , Johan G. Eriksson b,e,i,j a Department of Psychology, University of Helsinki, Helsinki, Finland b National Institute for Health and Welfare, Helsinki, Finland c Psychiatric Unit, Vaasa Central Hospital, Vaasa, Finland d Internal Medicine Unit; Vaasa Central Hospital, Vaasa, Finland e Department of General Practice and Primary Health Care, University of Helsinki, Helsinki, Finland f University of Helsinki, Hospital for Children and Adolescents, Helsinki, Finland g MRC Epidemiology Resource Centre, University of Southampton, Southampton, UK h DOHaD Centre, University of Southampton, Southampton, UK i Vasa Central Hospital, Vaasa, Finland j Unit of General Practice, Helsinki University Central Hospital, Helsinki, Finland abstract article info Article history: Received 19 January 2009 Received in revised form 3 July 2009 Accepted 27 August 2009 Available online xxxx Keywords: Body size at birth Head circumference Head-to-length ratio Birth weight Dramatic personality disorder Placental area Fetal growth Although a suboptimal prenatal environment has been linked with schizophrenia and depression, possible associations with personality disorders remain unclear. The aim of this study was to examine the associations of body size at birth and length of gestation with hospitalization for personality disorders in a cohort study of 6506 men and 5857 women born in Helsinki, Finland, between 1934 and 1944. International Classification of Diseases (-8, -9, -10) diagnoses of personality disorders were extracted from the national Finnish Hospital Discharge Register since 1969. 102 men and 80 women had been hospitalized due to any personality disorder. 41 men and 30 women had dramatic personality disorders. Among men, head circumference showed an inverse J-shaped, nonlinear association with hospitalization for personality disorders. Men with a small head circumference were at increased risk. Also in men, a smaller head-to-length ratio linearly predicted personality disorders. Among women, a smaller placental area predicted increased risk of hospitalization for dramatic personality disorders. Vulnerability to personality disorders may be programmed during fetal life. © 2009 Elsevier Ireland Ltd. All rights reserved. 1. Introduction A suboptimal prenatal environment (Roseboom et al., 2006), particularly as reflected in prematurity (Lawlor et al., 2006), and in a small body size at birth (Barker, 2004; Barker et al., 2005), is independently associated with an increased risk for cardiovascular disease (Barker, 2004; Barker et al., 2005; Roseboom et al., 2006) and type 2 diabetes (Barker, 2004; Lawlor et al., 2006; Roseboom et al., 2006). Another line of evidence suggests that a suboptimal prenatal environment (Brown et al., 2000; St Clair et al., 2005), shorter length of gestation (Byrne et al., 2007; Räikkönen et al., 2007), and small body size at birth (Wahlbeck et al., 2001; Cannon et al., 2002; Nilsson et al., 2005; Räikkönen et al., 2008) may also predict the risks of schizophrenia (Wahlbeck et al., 2001; Cannon et al., 2002; Nilsson et al., 2005; St Clair et al., 2005; Byrne et al., 2007) and depression (Brown et al., 2000; Räikkönen et al., 2007, 2008). These findings are in line with the Developmental Origins of Health and Disease (DOHaD) hypothesis, which suggests that a suboptimal prenatal environment may permanently alter developing organ structures and function of biological systems placing an individual at increased risk for diseases in subsequent life (Barker, 2004). Personality disorders are severe mental disorders with an estimated point prevalence rate between 4.4% (Coid et al., 2006) and 9% (Samuels et al., 2002). These disorders are associated with an increased risk for cardiovascular disease (Pietrzak et al., 2007) and are predictive of all- cause mortality and particularly of suicides (Neeleman, 2001). Elucidat- ing the etiological pathways to personality disorders is thus important for public health purposes. Although the DOHaD hypothesis might also shed light on the etiology of personality disorders, not much is known about the role played by prenatal factors in the development of personality disorders. The Dutch Famine studies showed associations between prenatal famine exposure and the development of schizoid (Hoek et al., 1996) and antisocial (Neugebauer et al., 1999) personality disorders among men. In a recent study in Sweden, preterm boys born Psychiatry Research xxx (2010) xxx–xxx ⁎ Corresponding author. Department of Psychology, University of Helsinki, PO Box 9, FI 00014 University of Helsinki, Finland. Tel.: +358 9 19129541; fax: +358 9 19129521. E-mail address: marius.lahti@helsinki.fi (M. Lahti). PSY-06307; No of Pages 5 0165-1781/$ – see front matter © 2009 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.psychres.2009.08.024 Contents lists available at ScienceDirect Psychiatry Research journal homepage: www.elsevier.com/locate/psychres ARTICLE IN PRESS Please cite this article as: Lahti, M., et al., Prenatal origins of hospitalization for personality disorders: The Helsinki Birth Cohort Study, Psychiatry Research (2010), doi:10.1016/j.psychres.2009.08.024