Toxoplasma Gondii Infection and Depression: A Case-Control Seroprevalence Study.

We assessed the association of Toxoplasma gondii infection and depression in a sample of psychiatric patients and control subjects without depression. We performed an age- and gender-matched case-control study of 89 patients suffering from depression attended in a public psychiatric hospital in Durango City, Mexico and 356 control subjects without depression from the general population of the same city. Participants were tested for the presence of anti-Toxoplasma IgG and IgM antibodies using enzyme-linked immunoassays. Anti-T. gondii IgG antibodies were found in 11 (12.4%) of the 89 cases and in 22 (6.2%) of the 356 controls (OR = 2.14; 95% CI: 1.00-4.59; P = 0.04). Anti-T. gondii IgM antibodies were found in four (19%) of 21 anti-T. gondii IgG seropositive controls but not in 11 anti-T. gondii IgG seropositive cases (P = 0.27). Patients aged 30 years old and younger had a significantly higher seroprevalence of T. gondii infection than controls of the same age group (P = 0.001). Results of the present study suggest a potential association between T. gondii infection and depression. Furthers studies to confirm our results and to determine the epidemiology of T. gondii in young depressed patients should be conducted.

Toxoplasma gondii Infection and Mixed Anxiety and Depressive Disorder: A Case-Control Seroprevalence Study in Durango, Mexico.

BACKGROUND: The parasite Toxoplasma gondii (T. gondii) may invade the brain and might induce behavioral changes. We sought to determine the association of T. gondii infection and mixed anxiety and depressive disorder. METHODS: Through an age- and gender-matched case-control seroprevalence study, we examined 65 patients suffering from mixed anxiety and depressive disorder (WHO ICD-10 code: F41.2) attending in a public hospital of mental health and 260 control subjects without this disorder from the general population. Sera of participants were analyzed for anti-Toxoplasma IgG and IgM antibodies using enzyme-linked immunoassays. RESULTS: Fifteen (23.1%) of the 65 patients and 18 (6.9%) of the 260 controls had anti-T. gondii IgG antibodies (odds ratio (OR): 4.03; 95% confidence interval (CI): 1.90 - 8.53; P < 0.001). The frequency of high (> 150 IU/mL) anti-T. gondii IgG levels was similar in cases and controls (OR: 0.25; 95% CI: 0.05 - 1.06; P = 0.05). Seroprevalence was similar in male cases and controls (P = 1.0); however, seroprevalence was significantly higher in female cases than in female controls (OR: 7.08; 95% CI: 2.83 - 17.67; P < 0.00001). Patients aged 31 - 50 years old had a significantly higher seroprevalence of T. gondii infection than controls of the same age group (OR: 21.04; 95% CI: 5.22 - 84.80; P < 0.00001). Anti-T. gondii IgM antibodies were found in four (26.7%) of the 15 anti-T. gondii IgG seropositive cases and in 10 (55.6%) of the 18 anti-T. gondii IgG seropositive controls (P = 0.15). CONCLUSIONS: Results support for the first time an association between seropositivity to T. gondii and mixed anxiety and depressive disorder. Further research to confirm this association and to determine the seroepidemiology of T. gondii infection in patients with this disorder is needed.