Correlates of Anti-Toxoplasma IgG Antibodies in Females with Borderline Personality Disorder: A Pilot Cross-Sectional Study

Neuropsychiatr Dis Treat. 2026 Apr 3;22:593736. doi: 10.2147/NDT.S593736. eCollection 2026.

ABSTRACT

BACKGROUND: Latent Toxoplasma gondii infection has been associated with various mental health conditions, but its potential role in the pathophysiology of borderline personality disorder (BPD) remains unclear. This pilot study investigated associations of anti-Toxoplasma IgG seropositivity with the severity of BPD symptoms among adult females with BPD.

METHODS: The sample consisted of 77 female patients diagnosed with BPD who were admitted for psychotherapeutic inpatient care for the personality disorder. T. gondii antibodies (IgG, IgA, and IgM) were measured using ELISA. Psychiatric and psychological assessments included Clinical Global Impression for BPD, Borderline Evaluation of Severity over Time, Buss-Perry Aggression Questionnaire, Suicide Behaviors Questionnaire-Revised, Beck Anxiety Inventory, and Beck Depression Inventory-II. Data were analyzed using descriptive statistics, Fisher’s exact test, χ ² test, t-tests, and Mann-Whitney U-tests.

RESULTS: Only nine patients (11.7%) were seropositive for T. gondii IgG antibodies. Although none of the hypothesized differences reached statistical significance, several medium-sized effects indicated potentially clinically relevant differences between the seropositive and seronegative groups. Specifically, the seropositive group reported more suicidal ideations during the past year (d = 0.67) and exhibited less severe symptoms of abandonment (d = 0.67) and depression (d = 0.57). The remaining symptoms showed small (suicidality, aggression, anger, and anxiety) or marginal (overall BPD severity, impulsivity) differences between the two groups.

CONCLUSION: This exploratory pilot study observed lower anti-Toxoplasma IgG seropositivity among patients with BPD than previously expected. Although the findings were not statistically significant, several trends indicated that seropositive patients might differ from the seronegative group. These preliminary results should be viewed as hypothesis-generating and validated in larger samples.

PMID:41952971 | PMC:PMC13055860 | DOI:10.2147/NDT.S593736