"A circle and a triangle dancing together": Alteration of social cognition in schizophrenia compared to autism spectrum disorders.

Difficulties in social cognition are present both in persons with schizophrenia (SCZ) and persons with autism spectrum disorders (ASD). However, qualitative similarities and differences in this field remain unclear. The aim of this study was to explore attribution of intentionality in patients with recent onset SCZ in comparison to patients with high functioning ASD, and to explore relationships between alterations in attribution and clinical profile. Animated shapes are a non-verbal Theory of Mind (ToM) task involving the interpretation of geometric figure interactions in three conditions: random, goal-directed and ToM. We compared 51 young adults with SCZ, 32 with ASD and 23 healthy controls (HC) matched for age and gender. In random, goal-directed and ToM conditions, persons with SCZ attributed less intentionality with less appropriate answers than HC, while the same anomalies were only found in the ToM condition in persons with ASD. In SCZ, thought and langage disorganization and earlier age at onset were correlated with intentionality score in the random condition. Moreover, a mixed ToM impairment was found in SCZ, combining undermentalizing (for movements involving a mental state) similar to what was found in ASD, and overmentalizing (for random movements), related to dizorganization and precocity of the first psychotic episode. In the frame of the hypothesis of a continuum, these results underline both similarities and differences between autism and schizophrenia.

Immunoglobulin sub-class distribution in bipolar disorder and schizophrenia: potential relationship with latent Toxoplasma Gondii infection.

BACKGROUND: Immune dysfunction could play a significant role in the pathogenesis of bipolar disorder (BD) and schizophrenia (SZ), conditions with an underlying pro-inflammatory state. Studies on humoral immune responses (which reflects antibody mediated fight against pathogens) in schizophrenia and bipolar disorder are sparse and often providing contradictory results. The aim of this study was to assess humoral immunity in a group of stable bipolar disorder and schizophrenia patients compared to controls by determining total Immunoglobulins and IgG subclasses and to assess their association with latent Toxoplasma gondii and/or CMV infection. METHODS: 334 subjects (124 BD, 75 SZ and 135 Healthy Controls [HC]) were included and tested for humoral immunity by determining the total immunoglobulins (IgG,A and M) and IgG subclasses (IgG1, IgG2, IgG3, IgG4) and their relationship with latent Toxoplasma gondii infection, an established risk factor for BD and SZ. RESULTS: Although lower levels of IgG, IgG1, IgG2, IgG4 and IgA were found among BD as compared to HC and/or SZ, after adjustment for confounding variables, only low levels of IgG and IgG1 in BD remai- ned significant. Strikingly highest levels of antibodies to T. gondii (but not CMV) infection in BD and SZ were associated with lowest levels of IgG3 and IgG4 levels as compared to controls. CONCLUSIONS: Schizophrenia and bipolar disorder patients with latent T. gondii specific infection may be more vulnerable to changes in immuno-inflammatory processes than controls with similar latent infectious state. Simultaneous sequential immunological monitoring both in steady state and active disease phases in the same BD and SZ patients are warranted to understand the role of Toxoplasma gondii latency in these disorders.

Effects of Cumulative Herpesviridae and Toxoplasma gondii Infections on Cognitive Function in Healthy, Bipolar, and Schizophrenia Subjects.

OBJECTIVE: Schizophrenia and bipolar disorder are associated with cognitive impairment leading to social disruption. While previous studies have focused on the effect of individual infectious exposure, namely, Herpesviridae viruses or Toxoplasma gondii (T gondii), on cognitive functioning, the objective of the present study was to examine the effect of multiple infections on cognitive functioning in patients with schizophrenia and bipolar disorder and in healthy controls. METHODS: Seropositivity to herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2), cytomegalovirus (CMV), and T gondii was related to cognitive status among 423 participants (recruited between 2008 and 2014; 138 patients with bipolar disorder, 105 patients with schizophrenia [DSM-IV criteria], and 180 healthy controls) for episodic verbal memory (California Verbal Learning Test), working memory (Wechsler Adult Intelligence Scale, third edition), and premorbid intelligence quotient (National Adult Reading Test). RESULTS: Seropositivity to and antibody levels of HSV-1 were significantly associated with working memory, which persisted after correction (backward digit span: ß = -0.10 [0.05], χ² = 33.89, P = .0001) in the overall sample. This association was particularly strong in the control group (ß = -0.18 [0.08], P = .04, Z = -3.55, P = .0008; corrected P = .012). Further, cumulative exposure to HSV-1, HSV-2, and CMV viruses and T gondii parasite was also associated with lower scores on working memory as measured by backward digit span in the overall sample (Z = 2.86, P = .004; Z = 2.47, P = .01; and Z = 3.35, P = .01, respectively). CONCLUSIONS: Exposures to Herpesviridae and T gondii parasite seem to impact cognitive functioning. Because infections caused by Herpesviridae and/or T gondii parasite are quite common in the (general) population, assessing and confirming the cognitive impairment among those who have cumulative exposures is useful and of interest.

Cognitive deterioration among bipolar disorder patients infected by Toxoplasma gondii is correlated to interleukin 6 levels.

BACKGROUND: Cognitive deficits are present in a large majority of Bipolar Disorder (BD) patients and known to be a marker of bad prognosis. Because, these deficits encompass several domains and no specific medical treatment seems to be effective, it is important to better understand the mechanisms underlying cognitive deterioration. As Toxoplasma gondii is known to induce the synthesis of pro-inflammatory cytokines such as IL-6, we will explore here the possible role of T. gondii in the cognitive decline observed in BD. METHODS: 42 euthymic BD patients and 36 controls were assessed for episodic verbal memory using the CVLT and for working memory and verbal ability using the WAIS III. Patients and controls were also screened for seropositivity to T. gondii and evaluated for the levels of IL-6 transcripts. RESULTS: The seropositivity for T. gondii was significantly higher in BD patients as compared to controls (p=0.005). The cognitive deterioration index (DI) was higher in BD patients (p=5.10(-6)) and correlated to high IL-6 mRNA expression only among those infected by T. gondii (rho=0.43, p=0.01). Among deteriorated patients (defined by scores above 0.10 according to Weschler׳s definition), the IL-6 mRNA expression was twice greater (p=0.01). LIMITATIONS: Our results are to be interpreted with caution because of our small sample size and the cross-sectional design. CONCLUSIONS: A long-term exposure to inflammation, measured here with IL-6 mRNA expression in T. gondii infected BD may alter cognitive functioning. IL-6 could thus be a useful predictive marker of cognitive deterioration in BD and may help to design personalized treatment.

Relationship between Toxoplasma gondii infection and bipolar disorder in a French sample.

BACKGROUND: Prenatal exposure to viruses or parasites with tropism for the central nervous system is one of the risk factors for psychotic disorders. However, the relationship between past exposure to Toxoplasma gondii (T. gondii) and incidence of bipolar disorders (BD) is poorly documented across populations. METHODS: We explored the potential association between T. gondii exposure and BD in France, a country of high prevalence of Toxoplasmosis, comparing the prevalence of serological markers (IgG/IgM class antibodies) for T. gondii infection in 110 BD patients and 106 healthy controls all living in France. In a subgroup of 42 patients and 42 controls we also evaluated the levels of interleukin 6 (IL-6) transcripts, an adjunct marker of inflammation. RESULTS: We found that the sero-positive group for IgG antibodies to T. gondii had a 2.7 fold odds of having BD as compared to the sero-negative group (OR=2.17 CI 95%=1.09-4.36, p=0.028). Despite the fact that BD patients had significantly higher levels of IL-6 than the non-patient controls, no notable association between T. gondii status and IL-6 transcript levels was found. We did not find any clinical or demographic correlates of Toxoplasma exposure in the study population. LIMITATIONS: Our results are to be interpreted with caution because of our small sample size. RESULTS: We confirm the association between seropositive status to T. gondii and bipolar disorders reported in other populations and extend it to French patients. Our data strengthen the importance of early detection of T. gondii infected patients in order to propose specific and adequate treatments.