[Do cognitive sciences open therapeutic paths in schizophrenia?].
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Animals↗
Biomedical subjects
M Saoud
Publications and source records attributed to M Saoud.
Repetitive transcranial magnetic stimulation does not potentiate antidepressant treatment.
In a double blind controlled study, rTMS results in a similar antidepressant effect to sham in combination with paroxetine. Both groups had the same delay in scale's scores improvement. rTMS seems not to be efficient as an add-on treatment to pharmacological medication in non-resistant major depression.
Antidepressive Agents, Second-Generation↗
Poor performance in smooth pursuit and antisaccadic eye-movement tasks in healthy siblings of patients with schizophrenia.
This study examines the area of eye movement dysfunctions as an indicator of vulnerability to schizophrenia. Eye movement performance was investigated with three different paradigms: Smooth Pursuit Eye Movements (SPEM); Visually Guided Saccades (VGS); and Antisaccades (AS) in 21 clinically stable patients with schizophrenia, 21 of their healthy, biological full siblings and 21 healthy control subjects. The three groups did not differ on VGS performance, whereas both patients and their siblings showed lower SPEM gain, an increased catch-up Saccades (CUS) rate, reduced AS accuracy and an increased number of AS errors in comparison to control subjects. In addition, patients with schizophrenia exhibited increased AS latency. Among the patients with schizophrenia, eye movement abnormalities did not correlate with age, gender, clinical state or duration of illness. These data suggest that abnormalities of SPEM and AS may represent neurobiological markers of the vulnerability to schizophrenia in individuals at high genetic risk for the disease.
Adult↗
Alteration of event related potentials in siblings discordant for schizophrenia.
This study was aimed at confirming that auditory event related potential (ERP) abnormalities are indicators of vulnerability to schizophrenia. Auditory ERP performances were assessed at Fz, Cz, and Pz, with an oddball paradigm, in 21 clinically stable patients with schizophrenia, 21 of their healthy biological full siblings and 21 control subjects. The evoked response did not differ between the three groups on N200 waves. Compared to controls, patients with schizophrenia exhibited reduced amplitudes of N100 and P300, and prolonged latency of P300, while their siblings showed prolonged latency of P200 and P300. Among the patients with schizophrenia, ERP abnormalities did not correlate with age, clinical state, duration of illness or antipsychotic treatments. Although other conditions also accounted for alterations of the same type, ERP abnormalities may represent a neurobiological marker of the genetic vulnerability to schizophrenia, independent of phenotypic expression.
Adult↗
Neuropsychological deficit in siblings discordant for schizophrenia.
This study was aimed, first, at detecting neuropsychological markers that assess vulnerability to schizophrenia in siblings of patients with schizophrenia, and second, at exploring possible relationships between markers. For these purposes, performances were assessed in 18 clinically stabilized patients with schizophrenia, 18 of their unaffected full siblings, and 15 controls on attentional abilities (the Degraded Stimuli-Continuous Performance Task [DS-CPT] and the Span of Apprehension [SOA] task) and on executive functions (the Wisconsin Card Sorting Test [WCST]). Both patients and siblings were impaired on the three tasks, leading to the conclusion that these poor performances may represent markers of genetic vulnerability to schizophrenia. Furthermore, significant relationships were found between DS-CPT and WCST performance in patients only, suggesting a possible implication of prefrontal brain areas for the two tasks. In spite of the lack of similar relationships between DS-CPT and WCST in siblings, this raises the question of a putative role of prefrontal areas in vulnerability to schizophrenia.
Adult↗
Attentional deficits in patients with schizophrenia and in their non-psychotic first-degree relatives.
The aim of this study was to investigate whether non-psychotic relatives of schizophrenic probands have deficits in sustained attention as measured by the Continuous Performance Test, Identical Pairs version (CPT-IP) and whether such deficits are associated with negative schizotypal personality disorders. The study subjects were 23 schizophrenic probands, 45 of their first-degree relatives and 36 normal controls. For each subject, attention was assessed during five conditions (2 standard, 2 slow, 1 easy) of visual stimuli (numbers and shapes). Schizotypy status was determined with the physical anhedonia and social anhedonia scales of Chapman et al. (Chapman, L.J., Chapman, J.P., Raulin, M.L., 1976. Scales for physical and social anhedonia. Journal of Abnormal Psychology 42, 374-382). The CPT-IP sensitive index d' in the standard shape condition was significantly lower in schizophrenics and in their relatives than in controls. For all d' values, the percentage of impaired first-degree relatives was at an intermediate level between patients and control individuals. Furthermore, the schizophrenic probands made more random errors in the standard and in the slow number conditions than the other two groups. None of the schizotypy measures correlated with the CPT-IP deficits. These results suggest that spatial sustained attention deficit may be a vulnerability marker for schizophrenia; however, this deficit and the negative dimension of schizotypal personality disorders may be distinct traits.
Adult↗
Neuropsychological functioning among non-psychotic siblings and parents of schizophrenic patients
Several studies have shown subtle neuropsychological deficits in healthy relatives of schizophrenic patients. However, older relatives and parents have been less frequently assessed than younger adult relatives and siblings. Furthermore, some areas of neuropsychological functioning such as memory and learning have been little studied. Thirty-seven 22-70-year-old non-psychotic parents and siblings of schizophrenic patients were compared to 37 healthy control subjects on a battery of neuropsychological tests (Trail Making, parts A and B, verbal fluency, Wisconsin Card Sorting Test, and four subtests of the Wechsler Memory Scale-Revised: logical memory, design reproduction, verbal paired associates and digit span). Relatives did not differ from control subjects on Wisconsin Card Sorting Test performance and on visual memory, but were significantly impaired on verbal fluency; more subtle deficits were found on Trail Making, part B, digit span and paired associates. A higher proportion of relatives than control subjects showed impairment on verbal fluency and verbal memory. These neuropsychological weaknesseswere present as much in siblings as in parents of schizophrenic patients, and age did not cancel differences between relatives and control subjects. Thus, these subtle deficits seem to be potential phenotypic markers of schizophrenia.
Journal Article↗
Auditory event-related potentials and clinical scores in unmedicated schizophrenic patients.
Event-related potentials (ERPs) have been widely examined in schizophrenic patients. However, although neuroleptic medication could be a potentially confounding variable, studies with unmedicated patients are relatively scarce. The present work was undertaken to determine whether ERP abnormalities persist in stabilized schizophrenic patients after drug withdrawal. In addition, ERP amplitudes and latencies were compared with clinical ratings (the Positive and Negative Syndrome Scale, PANSS) by means of Spearman rank order correlation coefficients. The P300 and N200 responses to rare tones and the P200 and N100 responses to frequent tones were recorded in 20 clinically stabilized drug-free schizophrenic patients and 19 age-matched control subjects during a two-tone discrimination task. Major findings were that the schizophrenic patients had reduced P300, N200 and N100 amplitudes and an increased P300 latency. The P300 amplitude was negatively correlated with age in patients. The P200 latency was negatively correlated with the PANSS positive syndrome score. The ERP abnormalities shown in this study appear to be enduring traits of the disorder as they persist in stabilized patients even after drug withdrawal.
Adult↗
[Interdependence of positive, negative and depressive symptoms in the course of schizophrenia without psychotic antecedents].
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Depressive Disorder↗
Olfactory identification deficiency and WCST performance in men with schizophrenia.
Several studies using the University of Pennsylvania Smell Identification Test (UPSIT), which requires forced choice olfactory identifications, have reported olfactory identification deficits in patients with schizophrenia. This report examines the possible links between olfactory identification (usually attributed to the orbitofrontal cortex) and executive functions (usually attributed to dorsolateral prefrontal cortex) in 24 male patients with schizophrenia and 21 male comparison subjects. Olfactory performance was investigated under two conditions: spontaneous identification and forced choice identification. Executive function was assessed with the Wisconsin Card Sorting Test (WCST). Compared with controls, patients with schizophrenia exhibited a higher average number of cigarettes smoked per day, lower spontaneous identification scores on olfactory performance, and a higher percentage of perseverative errors on the WCST; there was a significant relationship between the two performance measures. Simpson-Angus scores, neuroleptic drug treatment levels, and scores on the Positive and Negative Syndrome Scale were not correlated with either olfactory measure. The lack of correlation between the forced choice olfactory identification score and the WCST score is consistent with findings in previous studies that used the UPSIT. By contrast, use of a spontaneous identification condition to assess olfactory performance did produce a significant association with WCST performance.
Adult↗
Gaze discrimination is unimpaired in schizophrenia.
Interpersonal communication is largely dependent on interpretation of facial expression and emotion. Difficulties in face processing, and more specifically in gaze discrimination, have been described in schizophrenic patients. According to Baron-Cohen (Mindblindness. M.I.T. Press, Cambridge, MA, 1995), gaze discrimination relies on the functioning of a specific cognitive module, the Eye Direction Detector (EDD). It has been proposed [Rosse et al. (1994) Gaze discrimination in patients with schizophrenia: preliminary report. American Journal of Psychiatry 151, 919-921] that an impairment in gaze discrimination is present in schizophrenia, and plays a fundamental role in inducing the paranoid symptoms reported by many patients. However, in the previous studies, gaze direction detection and interpretation of gaze have never been completely dissociated. The present experiment attempts to test the schizophrenics' skill in a simple gaze direction detection task. A series of photographic portraits of models looking at different directions have been presented to 22 schizophrenic patients and 36 control subjects. For each portrait subjects were asked to determine whether gaze was directed to the right or to the left by pressing a keyboard key. A forced choice paradigm was used. No differences were reported between schizophrenic patients and control subjects. That is, in the present paradigm, schizophrenic patients did not show any specific impairment in detecting the direction of gaze of the portraits. The results are discussed according to the notion that a dissociation is present in schizophrenia between implicit and explicit processes. The present case illustrates how the more automatic elementary functions, such as the detection of gaze direction, may be spared in schizophrenic patients, whereas explicit cognitive functions are likely more affected.
Adult↗
[Risk factors and schizophrenia].
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Brain↗
[Impact of a new cognitive remediation strategy on interpersonal problem solving skills and social autonomy in schizophrenia].
INTRODUCTION: Despite recent developments, the impact of pharmacotherapy on social autonomy and interpersonal problem solving skills in patients with schizophrenia remains limited, with consequences in terms of socio-professional functioning. Indeed, independently of the positive, negative and/or disorganization symptoms, functional deficits in patients with schizophrenia rely mainly on various cognitive impairments. OBJECTIVES: To determine the impact of a new Cognitive Remediation Strategy on interpersonal problem solving skills, social autonomy and symptoms in patients with schizophrenia. METHODS: Thirty patients with schizophrenia were enrolled in a program consisting of 14 training sessions of 4 cognitive functions (attention/concentration, topological memory, logical reasoning, executive functions) using the REHACOM software. Measurements of attention (Continuous Performance Test, CPT), memory (Rivermead Behavioural Memory Test, RBMT) and executive functions (Wisconsin Card Sorting Test, WCST) as well as interpersonal problem solving skills (Assessment of Interpersonal Problem-Solving Skills, AIPSS) and social autonomy (Social Autonomy Scale, EAS) and finally schizophrenia symptoms (Positive And Negative Syndrom Scale, PANSS) were undertaken at the beginning and the end of the 14 remediation meetings. RESULTS: Cognitive functions, interpersonal problems solving skills, social autonomy and symptoms were significantly improved by the Cognitive Remediation Strategy. CONCLUSION: Our results confirm the therapeutic impact of a Cognitive Remediation Strategy among 30 schizophrenic patients stabilised on clinical, therapeutic and functional levels. The question of the long-term maintenance of such improvements still requires further investigation.
Adolescent↗
[Vulnerability to schizophrenia. II: Familial status of auditory evoked potential abnormalities].
The existence of a genetic background is well admitted in schizophrenia, but some individuals at genetic risk for that disease could never manifest it at a clinical level. However, several vulnerability models could help us to identify such individuals. According to them, when similar perturbations at a given task are observed both in clinically stable patients with schizophrenia and their nonschizophrenic first degree relatives, this task could be qualify as an indicator of the vulnerability to schizophrenia. In literature, that seems the case for auditory ERP late components in oddball paradigms. Our study was undertaken to replicate literature data. For that purpose, amplitude and latencies of auditory N100, P200, N200 and P300 wave-forms were assessed among 21 clinically, stable schizophrenics, 21 of their biological full siblings and 21 unrelated control subjects matched with the two others groups for several socio-demographic factors. Comparison were performed by non parametric analyses (Kruskal-Wallis one way ANOVA, and post-hoc Mann-Whitney). Compared to controls, delayed latencies and/or reduced amplitudes were observed for several ERP components--mainly with P300--in the sibling group. ERP values from this group did not statistically differ from those of the group with schizophrenia. In conclusion, results from the sibling group suggest that ERP impairments in auditory oddball paradigms may actually represent indicators of the genetic vulnerability to schizophrenia.
Adolescent↗
[Translation and French adaptation of the Raine Schizotypal Personality Questionnaire].
Most of existing self-report measures of schizotypal personality assess only few of the nine traits of schizotypal personality disorder according to DSM III-R or DSM IV. Adrian Raine has developed a self-report scale named "Schizotypal Personality Questionnaire, [SPQ]" to evaluate all these traits. The questionnaire was found to have high sampling validity, high internal reliability [0.91] and test-retest reliability [0.82]. However, the SPQ was still not available in French. Therefore, the first purpose of this report was to offer a French translation of this tool with the agreement of A. Raine for both translated version and its back translation. The second purpose of our study was to establish French norms. The preliminary norms presented here were obtained by administering the SPQ to a sample of 134 French students of both gender (mean age: 20.11 +/- 1.53 years; mean educational level: 13.39 +/- 1.04 years). On that sample, the minimal score was 2/74 and the maximal one 54/74 (mean of the sample: 23.60 +/- 12.09). With the original English study, based on a sample of American students, the cut-offs for the top and the bottom ten percents of SPQ scores were respectively of 41/74 and 12/74. Very close preliminary cut-offs were observed in our own study i.e. respectively 40/74 and 9/74. We will confirm them in a larger sample.
Adult↗
[French translations and adaptations of questionnaires of magical thinking (MIS, Eckblad and Chapman, 1983) and perception disorders (PAS, Chapman et al., 1978)].
Meehl used the term "schizotype" to refer to individuals who possess an underlying vulnerability for schizophrenia. Because of the extremely varying degrees of the schizotype's clinical expression, he recommended assessing schizotypic signs through objective measures rather than clinical judgement. In this way, Chapman et al. have developed symptom-oriented scales based on Meehl's manual, such as the Social Anhedonia (SA) and Physical Anhedonia (PhA) Scales, the Magical Ideation Scale (MIS), the Perceptual Aberration Scale (PAS) and the Impulsive Nonconformity Scale (IN). Whereas Chapman's scales of psychosis proneness are the most internationally used instruments for the assessment of schizotypy, some of them, such as MIS and PAS, were still not available in French. Therefore, the first aim of this report was to offer French translations of the Magical Ideation and the Perceptual Aberration Scales; the agreement of the original authors were obtained for both translated versions and their back translations. The second aim of our study was to establish French norms for each of these scales. The preliminary norms presented here [MIS: 19/30 (for females) and 20/30 (for males); PAS: 18/35 (for both genders)] were obtained by administering both scales to a sample of 134 French students. They are very close to those found by Chapman et al. for University of Wisconsin undergraduate students. We will confirm them with a larger sample of French students.
Adult↗
[Validation of French versions of magical ideation and perceptual aberrations questionnaires].
Chapman and colleagues have developed symptom-oriented scales based on Meehl's manual of schizotypy, such as the Social Anhedonia (SA) and Physical Anhedonia (PhA) Scales, the Magical Ideation Scale (MIS), and the Perceptual Aberration Scale (PAS). Whereas Chapman's scales of psychosis proneness are the most internationally used instruments for the assessment of schizotypy, some of them, such as MIS and PAS, were still not available in French. We reported here the validation study of the MIS and the PAS French versions that we had published previously. This study was conducted in a sample of 233 students (males: n = 108; females: n = 125; mean age: 21.17 +/- 1.47; mean educational level: 13.36 +/- 1.06). The French versions of the MIS and the PAS have high internal reliability (MIS: Cronbach's alpha = 0.85; PAS: Cronbach's alpha = 0.88). French norms are given for each of these scales. They are respectively 19/30 for the MIS and 17/35 for the PAS high cutoff scores without any difference when gender was considered. These results are very closed to those found by Chapman and colleagues for University of Wisconsin undergraduate students.
Adult↗
[Validation of the French version of the Raine Schizotypal Personality Disorder Questionnaire--categorial and dimensional approach to schizotypal personality traits in a normal student population].
Most of existing self-report measures of schizotypal personality assess only few of the nine traits of Schizotypal Personality Disorder (SPD) according to DSM III-R or DSM IV. The Raine's Schizotypal Personality Questionnaire (SPQ) is one of the most widely used questionnaire for SPD diagnosis. This well adapted tool for screening SPD in large samples from general population allows simple and quick evaluations by the mean of 74 items and nine sub-scales exploring DSM IV criteria of the trouble. With the original sample of American students, Raine found SPQ to have high internal reliability (0.91) and reported cutoffs for the top and the bottom ten percents of SPQ scores at respectively 41/74 and 12/74. We reported here the validation study of the French version of the SPQ in a sample of 232 students (males: n = 107; females: n = 125; mean age: 21.17 +/- 1.47; mean educational level: 13.36 +/- 1.06). The French version has high internal reliability (SPQ total: Cronbach's alpha = 0.91; SPQ nine subscales: Cronbach's alpha = 0.57 to 0.76). The ten percent high and low cutoff scores on the distribution of SPQ scores are respectively 40/74 and 7/74 for the total sample. However, gender differences are observed: 38/74 and 9/74 for females; 42/74 and 6/74 for males. A Principal Component Analysis (PCA) confirms the high internal reliability. Moreover, PCA evidences a three-factor model of schizotypy reflecting "positive or cognitive-perceptual", "negative or social-interpersonal", and "disorganization" latent factors. These results replicate previous works on the topic with the same instrument.
Adolescent↗