The Association Between Suicide Attempts and Infection

Objective: Chronic 'latent' infection by is common and most of the hosts have minimal symptoms or they are even asymptomatic. However, there are possible mechanisms by which may affect human behavior and it may also cause humans to attempt suicide. This article aimed to investigate the potential pathophysiological relationship between suicide attempts and infection in Korea.

Methods: One hundred fifty-five psychiatric patients with a history of suicide attempt and 135 healthy control individuals were examined with enzyme-linked immunoassays and fluorescent antibody technique for seropositivity and antibody titers. The group of suicide attempters was interviewed regarding the history of suicide attempt during lifetime and evaluated using 17-item Korean version of Hamilton Depression Scale (HAMD), Columbia Suicide Severity Rating Scale (C-SSRS), State-Trait Anxiety Inventory (STAI) and Korean-Barratt Impulsiveness Scale (BIS).

Results: Immunoglobulin G antibodies were found in 21 of the 155 suicide attempters and in 8 of the 135 controls (=0.011). The Toxoplasma-seropositive suicide attempters had a higher HAMD score on the depressed mood and feeling of guilt subscales and a higher total score than the seronegative suicide attempters. seropositive status was associated with higher C-SSRS in the severity and lethality subscales. IgG seropositivity was significantly associated with higher STAI-X1 scores in the suicide attempters group.

Conclusion: Suicide attempters showed higher seroprevalence of than healthy controls. Among the suicide attempters, the seropositive and seronegative groups showed several differences in the aspects of suicide. These results suggested a significant association between infection and psychiatric problems in suicidality.