Theory of mind and schizophrenia in young and middle-aged patients: Influence of executive functions.

Theory of Mind (ToM) is compromised in schizophrenia, and responsible for social disability. We aim to study the correlation between ToM deficits and Executive Functions (EF), using the Faux Pas Test (FPT) for ToM evaluation, Behavioral Assessment of the Dysexecutive Syndrome (BADS) and Wisconsin Card Sorting Test (WCST) for EF assessment. Two groups of patients with schizophrenia were included: 22 young (18-35 years-old) and 18 middle-aged (>50 years-old) Patients, compared to age-matched Controls. We found worst FPT performances in both groups of patients, but with a more generalized pattern of dysfunction in the middle-aged patient group. This group had worse EF scores than both controls and younger patients. The association of EF with FPT items was uneven. In young patients only empathy (Q6) remained significant after controlling for EF and level of education, while in middle-aged patients faux pas explanation (Q4), false belief (Q5) and total scores remained significant. In young patients only affective TOM was impaired. No correlation was found with clinical symptoms, nor age at onset of the disease. We conclude that ToM deficit arises early during the course of the illness (already present in young patients), increases in middle-aged patients, and relates only partially with EF.

Saccadic eye movements as markers of schizophrenia spectrum: Exploration in at-risk mental states.

Schizophrenia is a neurodevelopmental disease with cognitive and motor impairments. Motor dysfunctions, such as eye movements or Neurological Soft Signs (NSS), are proposed as endophenotypic markers. Antisaccade (AS) and memory-guided saccades (MGS), two markers of inhibitory control mechanism, are altered in both patients with schizophrenia and their relatives, although these tools may have different sensitivities. Recently, emphasis has been put on identifying markers predictive of psychosis transition in subjects with ultra-high-risk psychosis in order to develop targeted prevention. This study investigates AS and MGS in 46 patients with schizophrenia, 23 ultra-high-risk subjects, and 39 full siblings compared to 47 healthy volunteers. NSS were assessed as a marker of abnormal neurodevelopment. The results revealed more errors in MGS in patients, ultra-high-risk subjects and siblings, than in controls, and more specifically ultra-high-risk subjects with high NSS scores. By contrast, the error rate in AS was significantly higher only in patients with schizophrenia compared to controls. These findings suggest that MGS could be more accurate to detect deficient inhibitory processes as a marker of vulnerability before the onset of schizophrenia. The use of the different paradigms (AS, MGS) revealed distinct profiles depending on the stage of the disease, indicating that some alterations could be pure endophenotypic markers of vulnerability for schizophrenia, while others could be markers of the disease progression.

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.