August 21, 2012 — Individuals infected with the Toxoplasma gondii parasite are at significant risk for later suicide attempts, new research suggests.
A cohort study of 84 adults from Sweden showed that those who had been infected with T gondii were 7 times more likely to participate in nonfatal, self-directed violence compared with their counterparts who had not been infected.
The abstract of the article below on this subject appeared in the Journal of Clinical Psychiatry:
Toxoplasma gondii Immunoglobulin G Antibodies and Nonfatal Suicidal Self-Directed Violence
Yuanfen Zhang, MD, PhD; Lil Träskman-Bendz, MD, PhD; Shorena Janelidze, PhD; Patricia Langenberg, PhD; Ahmed Saleh, PhD; Niel Constantine, PhD; Olaoluwa Okusaga, MD; Cecilie Bay-Richter, PhD; Lena Brundin, MD, PhD; and Teodor T. Postolache, MD
J Clin Psychiatry 2012;73(8):1069–1076
10.4088/JCP.11m07532
Copyright 2012 Physicians Postgraduate Press, Inc.
Objective: The primary aim was to relate Toxoplasma gondii seropositivity and serointensity to scores on the self-rated Suicide Assessment Scale (SUAS-S). Another aim was to reevaluate the previously reported positive association between T gondii serointensity and a history of nonfatal suicidal self-directed violence.
Method: This cross-sectional, observational study compared T gondii serointensity and seropositivity in plasma from 54 adult suicide attempters (inpatients at Lund University Hospital, Lund, Sweden) and 30 adult control subjects (randomly selected from the municipal population register in Lund, Sweden) recruited between 2006 and 2010. The potential of patients and controls for self-directed violence was evaluated with the SUAS-S. Psychiatric diagnoses were made according to DSM-IV criteria. Plasma samples were tested for immunoglobulin G antibodies to T gondii, cytomegalovirus, and herpes simplex virus type 1. Data were analyzed using multivariable logistic regression to investigate the association between T gondii serointensity or seropositivity and a history of nonfatal suicidal self-directed violence; multivariable linear regression was used to explore the relationship between T gondii serointensity or seropositivity and the SUAS-S. Both regression models included sex, age, and body mass index as covariates.
Results: Seropositivity of T gondii (adjusted odds ratio [OR] = 7.12; 95% CI, 1.66–30.6; P = .008) and serointensity of T gondii (adjusted OR = 2.01; 95% CI, 1.09–3.71; P = .03) were positively associated with a history of nonfatal suicidal self-directed violence. Seropositivity of T gondii was associated with higher SUAS-S scores, a relationship significant for the whole sample (P = .026), but not for suicide attempters only. No significant associations with other pathogens were identified.
Conclusions: These results are consistent with previous reports on the association between T gondii infection and nonfatal suicidal self-directed violence. Confirming these results in future large longitudinal studies and including suicide as an outcome may lead to novel individualized approaches in suicide prevention.
J Clin Psychiatry
© Copyright 2012 Physicians Postgraduate Press, Inc.
Submitted: November 11, 2011; accepted April 3, 2012.
Online ahead of print: July 10, 2012 (doi:10.4088/JCP.11m07532).
Corresponding author: Teodor T. Postolache, MD, Mood and Anxiety Program, Department of Psychiatry, University of Maryland School of Medicine, 685 West Baltimore St, MSTF Bldg, Room 930, Baltimore, MD 21201 (tpostolache@psych.umaryland.edu).