Schizophrenia and toxoplasmosis: association with catatonic symptoms.

INTRODUCTION

The association between schizophrenia and toxoplasmosis has been demonstrated in a number of studies: the prevalence of schizophrenia is significantly higher in toxoplasmosis positive subjects than in those with negative status. However, the clinical significance of this association remains poorly understood.

OBJECTIVES

To identify clinical phenomena that are typical for toxoplasmosis-associated ( seropositive) schizophrenia compared to Toxoplasma-seronegative schizophrenia.

METHODS

A retrospective database analysis of serum samples from 105 inpatients with schizophrenia (ICD-10code: F20; including 55 male patients; mean age of 27.4 6.4 years) was carried out. The clinical examination involved a structured interview including ICD-10 and E. Bleulers criteria for schizophrenia and psychometric tests(Positive and Negative Scales of PANSS). Serum antibodies (IgG) to were identified using ELISA. The statistical significance of any differences were evaluated using the non-parametric Mann-Whitney (U) and X tests.

RESULTS

The proportion of seropositive patients in the sample was 16.2%. Comparing schizophrenia patients, who were seropositive or seronegative for toxoplasmosis, there were no statistically significant differences for the mean total PANSS score, mean PANSS-P, PANSS-N or PANSS-G scores. For the majority of PANSS items, differences were also statistically insignificant, except for G5 and G6mannerism and posturing. Seropositive patients had a higher score for this item than seronegative patients: 3.5 versus 2.1 points (U=389.5; р=0.001). Depression, on the contrary,was less pronounced in seropositive than seronegative patients: 1.4 versus 2.4 points (U=509.5; р=0.023). In addition,in seropositive patients, the frequency of symptoms such as mutism according to ICD-10 criteria for schizophrenia was significantly higher (23.5% versus 3.4%, X=9.27, р=0.013), and the whole group of catatonic symptoms according to the E. Bleulers criteria for schizophrenia was higher (52.9% versus 28.4%, X=3.916, p = 0.048).

CONCLUSION

The association between a positive toxoplasmosis status in patients with schizophrenia and catatonic symptoms has been revealed for the first time and should be verified in larger studies.