Publications (10)32.32 Total impact
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Article: The CNR1 gene as a pharmacogenetic factor for antipsychotics rather than a susceptibility gene for schizophrenia.
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ABSTRACT: Neurobiological research suggests a significant role of the endocannabinoid system in schizophrenia vulnerability and also in the quality of response to antipsychotics. Genetics offer an opportunity to disentangle its involvement in the disease vulnerability vs an influence on antipsychotics' effects. The possible role of a tag SNP (the 1359G/A polymorphism) of the gene encoding the cannabinoid receptor type 1 (CNR1) in schizophrenia and/or therapeutic response to atypical antipsychotics was assessed in a cohort of 133 French schizophrenic patients compared to 141 normal control subjects. No difference in 1359G/A polymorphism was observed between patients and control subjects, and no relationships were noted between this polymorphism and any clinical parameter considered as potential intermediate factor. However, the G allele frequency was significantly higher among non-responsive vs responsive patients, with a dose effect of the G allele. In contrast, no association was found for three other genetic polymorphisms of the CNR1 gene. The G allele of the CNR1 gene polymorphisms could be a psychopharmacogenetic rather than a vulnerability factor regarding schizophrenia and its treatment.European Neuropsychopharmacology 02/2008; 18(1):34-40. · 4.05 Impact Factor -
Article: Elaboration of a rehabilitation method based on a pathogenetic hypothesis of "theory of mind" impairment in schizophrenia.
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ABSTRACT: "Theory of mind" skills have repeatedly been shown to be impaired in schizophrenic patients. The purpose of this paper is to develop a therapeutic intervention targeting schizophrenic patients' abilities to attribute mental states to others. This preliminary study tried to test the hypothesis that this kind of intervention should improve patients' communication abilities; we also wondered if this would have a positive impact on their more general psychopathology. Eight chronic schizophrenic patients were asked to analyse video scenes (showing interactions between two or more persons), with particular attention being paid to the characters' mental states. Their clinical assessments (general clinical symptoms, communication, and the ability to attribute intentions to others, rated before and after two training sessions, over a one-week period) were compared with those of a control group of six chronic schizophrenic patients. The results support our hypothesis of a possible improvement of patients' communication disorders and an improvement of their abilities to attribute intentions to others. The more general psychopathology ratings, however, remained unchanged. Although these results need further development and confirmation, they suggest a possible promising approach for psychosocial rehabilitation therapies based on "theory of mind" skills.Neuropsychological Rehabilitation 03/2006; 16(1):83-95. · 1.72 Impact Factor -
Article: Scale for the evaluation of communication disorders in patients with schizophrenia: a validation study.
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ABSTRACT: A scale for the evaluation of communication disorders in patients with schizophrenia (Schizophrenia Communication Disorder Scale-SCD) is proposed based on studies showing that cognitive disorders specific to the disorganization seen in schizophrenia consist of context processing deficits and problems in the attribution of mental states. Thus the focus of this scale is on the cognitive difficulties revealed in conversation during a structured interview. Fifty-six patients with schizophrenia, depression or mania were evaluated. Significantly elevated scores on the SCD were present in patients with schizophrenia compared to all other groups. Thus, this scale adds to the tools available for evaluating the language of patients with schizophrenia and helps focus on characteristics that are specific to this psychotic diagnosis.Schizophrenia Research 10/2005; 77(1):75-84. · 4.75 Impact Factor -
Article: Reasoning about physical causality and other's intentions in schizophrenia.
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ABSTRACT: Several studies have shown that schizophrenic patients have impaired theory-of-mind skills involving the attribution of false beliefs and intentions to others. Despite the methodological difficulties of false belief protocols, experiments have concluded that the deficit is specific and cannot be explained in terms of a general cognitive impairment. The situation, however, remains unclear as far as the attribution of intentions to others is concerned. We propose the use of nonverbal control tasks based on physical causality to demonstrate the specificity of the impairment of attribution of intentions. We compared the performances of schizophrenic patients and normal subjects on the attribution of intentions and on two control tasks involving physical causality (reasoning about the weight, location, speed, and the physical properties of objects). 25 schizophrenic patients and 25 healthy subjects participated in the study. Each subject was assessed under three conditions using comic strips: attribution of intentions, physical causality with characters, physical causality without characters. The performances of schizophrenic patients differed significantly from those of healthy subjects only in the attribution of intentions condition. This difference was also found when only subjects having optimal performances in physical logic were considered and when verbal IQ was considered as a co-variable. Nonverbal attribution of intentions to others is specifically impaired in schizophrenia. This conclusion is in agreement with recent neuroimaging findings.Cognitive Neuropsychiatry 06/2003; 8(2):129-39. -
Article: The cognitive basis of disorganization symptomatology in schizophrenia and its clinical correlates: toward a pathogenetic approach to disorganization.
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ABSTRACT: This article focuses on the schizophrenic disorganization syndrome, which was initially described by Bleuler (who used the term "dissociation") as lying at the heart of schizophrenia. While adopting a neo-Bleulerian approach, we describe schizophrenic disorganization using a pathogenetic hypothesis and a three-part structure. First, we discuss previous approaches to characterizing and defining schizophrenic disorganization, providing arguments in favor of a complementary approach to describing schizophrenic disorganization that relies on a pathogenetic analysis of the disorganization syndrome, and especially thought and language disorders. Second, we present two possible cognitive pathophysiological mechanisms that may explain schizophrenic disorganization: (1) a deficit in the integration of contextual information, based on the results of semantic priming studies; and (2) a theory of mind deficit, based on the results of studies of the attribution of mental states to others. We propose a cognitive model of schizophrenic dysfunctioning on the basis of these two anomalies. Third, we summarize our published findings to examine the implications of these two cognitive pathophysiological mechanisms for schizophrenic disorganization. On the basis of the same two anomalies, we then propose and illustrate a neo-Bleulerian approach to the assessment of communication disorders that is critical to the improvement of schizophrenic disorganization's clinical description.Schizophrenia Bulletin 02/2003; 29(3):459-71. · 8.80 Impact Factor -
Article: Cathartic effect of suicide attempts not limited to depression: a short-term prospective study after deliberate self-poisoning.
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ABSTRACT: The cathartic effect of suicide is traditionally defined as the existence of a rapid, significant, and spontaneous decrease in the depressive symptoms of suicide attempters after the act. This study was designed to investigate short-term variations, following a suicide attempt by self-poisoning, of a number of other variables identified as suicidal risk factors: hopelessness, impulsivity, personality traits, and quality of life. Patients hospitalized less than 24 hours after a deliberate (moderate) overdose were presented with the Montgomery-Asberg Depression and Impulsivity Rating Scales, Hopelessness scale, MMPI and World Health Organization's Quality of Life questionnaire (abbreviated versions). They were also asked to complete the same scales and questionnaires 8 days after discharge. The study involved 39 patients, the average interval between initial and follow-up assessment being 13.5 days. All the scores improved significantly, with the exception of quality of life and three out of the eight personality traits. This finding emphasizes the fact that improvement is not limited to depressive symptoms and enables us to identify the relative importance of each studied variable as a risk factor for attempted suicide. The limitations of the study are discussed as well as in particular the nongeneralizability of the sample and setting.Crisis The Journal of Crisis Intervention and Suicide Prevention 02/2003; 24(2):73-8. · 1.09 Impact Factor -
Article: Abnormalities of brain function during a nonverbal theory of mind task in schizophrenia.
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ABSTRACT: Theory of mind (ToM), the specific ability to attribute thoughts and feelings to oneself and others is generally impaired in schizophrenia. Previous studies demonstrated a deficit of the attribution of intentions to others among patients having formal thought disorder. During nonverbal tasks, such a function requires both the visual perception of human figures and the understanding of their intentions. These processes are considered to involve the superior temporal sulcus and the medial prefrontal cortex, respectively. Are the functional patterns of activation associated with those processes abnormal in schizophrenia? Seven schizophrenic patients on medication performed a nonverbal attribution of intentions task as well as two matched physical logic tasks, with and without human figures, while H2O15 PET-scanning was performed. Data from the patients were compared to those of eight healthy controls matched for verbal IQ and sex. The experimental design allowed dissociating the effect of the perception of human figures from that of the attribution of intentions. During attribution of intentions, significant activations in the right prefrontal cortex were detected in the control subjects. Those activations were not found in the schizophrenic group. However, in both groups, the perception of human figure elicited bilateral activation of the occipitotemporal regions and of the posterior part of the superior temporal sulcus. Schizophrenic patients performing a nonverbal attribution of intentions task have an abnormal cerebral activity.Neuropsychologia 02/2003; 41(12):1574-82. · 3.64 Impact Factor -
Article: Could cognitive vulnerability identify high-risk subjects for schizophrenia?
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ABSTRACT: This review puts into questions the possible role of cognitive vulnerability markers in prediction and prevention of schizophrenia. Until recently, none of the identified cognitive anomalies has been proved to be definitive. However, as new promising candidates are emerging (DS-CPT, CPT-IP, P suppression, Saccadic Eye Movements), the predictive value of these trait-type anomalies may be criticized regarding four issues, which are discussed: technical, metrological, theoretical, and clinical. As things stand, the existence of a cognitive vulnerability marker, which testify to a permanent pathological trait, does not constitute a sufficient factor to identify and treat subjects who are at risk for schizophrenia.American Journal of Medical Genetics 01/2003; 114(8):893-7. -
Article: Association of 5-HT(2A) receptor gene polymorphism with major affective disorders: the case of a subgroup of bipolar disorder with low suicide risk.
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ABSTRACT: The implication of serotonin in suicide and affective disease explains why the 5-HT(2A) receptor gene has been proposed as a candidate gene in these disorders, although with conflicting results. We analysed the distribution of the 5-HT(2A)-1438A/G genetic polymorphism in 192 patients with major affective disorder (127 bipolar disorders and 65 unipolar disorders) compared to 142 healthy control subjects. We found a higher frequency of the A allele in affected patients than in control subjects (p =.034), this difference being particularly striking for the subgroup of patients with type I bipolar disorder (p =.015). Patients with no personal and/or familial history of suicide attempts mainly accounted for the excess of the A allele in affected patients. The association detected in this study suggests that the 5-HT(2A) receptor gene may play a role in the genetic susceptibility to bipolar disorder, through a specific subgroup of bipolar type I patients with lower risk of suicidal behavior.Biological Psychiatry 06/2002; 51(9):762-5. · 8.28 Impact Factor -
Article: A PET Investigation of the Attribution of Intentions with a Nonverbal Task
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ABSTRACT: Several authors have demonstrated that theory of mind is associated with a cerebral pattern of activity involving the medial prefrontal cortex. This study was designed to determine the cerebral regions activated during attribution of intention to others, a task which requires theory-of-mind skills. Eight healthy subjects performed three nonverbal tasks using comic strips while PET scanning was performed. One condition required subjects to attribute intentions to the characters of the comic strips. The other two conditions involved only physical logic and knowledge about objects' properties: one condition involved characters, whereas the other only represented objects. The comparison of the attribution of intention condition with the physical logic with characters condition was associated with rCBF increases in the right middle and medial prefrontal cortex including Brodmann's area (BA) 9, the right inferior prefrontal cortex (BA 47), the right inferior temporal gyrus (BA 20), the left superior temporal gyrus (BA 38), the left cerebellum, the bilateral anterior cingulate, and the middle temporal gyri (BA 21). The comparison of the physical logic with characters condition and the physical logic without characters condition showed the activation of the lingual gyri (BA 17, 18, 19), the fusiform gyri (BA 37), the middle (BA 21) and superior (BA 22, 38) temporal gyri on both sides, and the posterior cingulate. These data suggest that attribution of intentions to others is associated with a complex cerebral activity involving the right medial prefrontal cortex when a nonverbal task is used. The laterality of this function is discussed.NeuroImage.
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2003–2006
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Centre Hospitalier de Versailles
Versailles, Ile-de-France, France
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