ORIGINAL PAPER Anne E. Rhodes Æ Jennifer Bethell Æ Julie Spence Æ Paul S. Links Æ David L. Streiner Æ R. Liisa Jaakkimainen Age–sex differences in medicinal self-poisonings A population-based study of deliberate intent and medical severity Received: 30 July 2007 / Accepted: 26 March 2008 / Published online: 29 May 2008 j Abstract Background Deliberate self-harm (DSH) is related to suicide and DSH repetition is common. DSH hospital presentations are often self-poisonings with medicinal agents. While older age and male sex are known risk factors for suicide, it is unclear how these factors are related to the nature and severity of medicinal self-poisoning (SP). Such knowledge can guide prevention strategies emphasizing detecting and treating mental illness and controlling access to means. Methods Medicinal SP presentations by 18,383 residents of Ontario, Canada, aged 12 years and older, who presented to a hospital emergency department in that province between April 1, 2001–March 31, 2002 were characterized by the agents taken, identification of deliberate intent and medical severity. Results We found distinct age-sex differences in the nature and severity of medicinal SP. In youths, aged 12–17, about 40% of presentations involved analgesics, typically not prescribed and most often the acetaminophen agent- group. Females aged 12–64 were identified as delib- erate more often than their male counterparts and this pattern occurred in most agent-groups, even among those who took antidepressants. The acetaminophen agent-group was most consistently associated with medical severity and this effect was strongest among female youths. Although medicinal SP was less frequent in the elderly, these presentations tended to be more medically serious and less often identified deliberate. Conclusions The high proportion of med- icinal SP in youths involving agents typically not prescribed and the medical severity of the acet- aminophen agent-group underscore how prevention strategies must extend beyond controlling access to antidepressants. Despite a higher risk for suicide, males and the elderly may not have their deliberate intent detected and therefore, may not receive Dr. A.E. Rhodes, PhD (&) Æ J. Bethell, MSc Prof. P.S. Links, MD, FRCP, MSc Suicide Studies Unit, St Michael’s Hospital 2 Shuter Wing (2010f), 30 Bond Street Toronto (ON) M5B 1W8, Canada Tel.: +1-416/360-4000 ext.-2693 Fax: +1-416/864-5996 E-Mail: rhodesa@smh.toronto.on.ca Dr. A.E. Rhodes, PhD Æ Prof. P.S. Links, MD, FRCP, MSc Prof. D.L. Streiner, PhD Dept. of Psychiatry, Faculty of Medicine University of Toronto Toronto (ON), Canada Dr. A.E. Rhodes, PhD Æ J. Bethell, MSc Dept. of Public Health Sciences, Faculty of Medicine University of Toronto Toronto (ON), Canada Dr. A.E. Rhodes, PhD Æ R.L. Jaakkimainen, MD, MSc The Institute for Clinical Evaluative Sciences Toronto (ON), Canada J. Spence, MD, MSc Chair Division of Emergency Medicine University of Toronto Toronto (ON), Canada J. Spence, MD, MSc Chair Research Ethics Board, St Michael’s Hospital Toronto (ON), Canada Prof. P.S. Links, MD, FRCP, MSc The Arthur Sommer Rotenberg Chair in Suicide Studies University of Toronto Toronto (ON), Canada Prof. D.L. Streiner, PhD Kunin-Lunenfeld Applied Research Unit, Baycrest Centre Toronto (ON), Canada R.L. Jaakkimainen, MD, MSc Dept. of Family and Community Medicine Faculty of Medicine University of Toronto Toronto (ON), Canada R.L. Jaakkimainen, MD, MSc Sunnybrook Health Sciences Centre Toronto (ON), Canada Soc Psychiatry Psychiatr Epidemiol (2008) DOI 10.1007/s00127-008-0349-6 SPPE 349