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Biomedical subjects

M Leboyer

Publications and source records attributed to M Leboyer.

At least 37 records · Page 2Linked to original sources
PubMed2000

Opiate antagonists in children and adolescents.

Naltrexone a pure opioid antagonist, well tolerated in young patients, has been found to be an interesting treatment in some disorders in children and adolescents. Naltrexone has been first tried in mental retardation and autism disorders in children and adolescents. Symptoms like self-injury behaviours, hyperactivity, stereotyped and ritualistic conducts appear to be improved in a subgroup of children with the opiate antagonist. But new controlled studies still need to be done before recommending naltrexone in autism. Preliminary results in the treatment of alcoholic adolescents seem to support the efficacy of naltrexone on abstinence when combined with a supportive psychotherapy. In adults, results found with the use of naltrexone in eating disorders are different, when considering the duration and the dosage of the treatment and the kind of eating disorder (bulimia, binge eating or anorexia nervosa). Studies in children and adolescents are needed before proposing naltrexone in eating disorders. We resumed here the results found with this treatment in these indications.

Adolescent↗
PubMed2000

Early and late onset bipolar disorders: two different forms of manic-depressive illness?

BACKGROUND: Conflicting results in genetic studies of bipolar disorders may be due to the clinical and genetic heterogeneity of the disease. Age at onset of bipolar disorders may be a key indicator for identifying more homogeneous clinical subtypes. We tested whether early onset and late onset bipolar illness represent two different forms of bipolar illness in terms of clinical features, comorbidity and familial risk. METHODS: Among a consecutively recruited sample of 210 bipolar patients, we compared early onset (n=58) and late onset (n=39) bipolar patients; the cut-off points were age at onset before 18 years and after 40 years for the two subgroups. The subgroups were compared by independent t tests and a contingency table by raw chi-square test. Morbid risk among first-degree relatives was measured by the survival analysis method. RESULTS: The early onset group had the most severe form of bipolar disorder with more psychotic features (P=0.03), more mixed episodes (P=0.01), greater comorbidity with panic disorder (P=0.01) and poorer prophylactic lithium response (P=0.04). First degree relatives of early onset patients also had a higher risk of affective disorders (P=0.0002), and exhibit the more severe phenotype, i.e bipolar disorder. CONCLUSION: Our data suggest that early and late onset bipolar disorders differ in clinical expression and familial risk and may therefore be considered to be different subforms of manic-depressive illness.

Adolescent↗
PubMed2000

The DRD2 gene and the risk for alcohol dependence in bipolar patients.

The high co-morbidity between bipolar disorder and alcohol dependence may have different explanations, one of them being the existence of common genetic factors for the two disorders. Several candidate genes may be involved but the genes acting in the dopaminergic pathway may be more specifically involved. We have thus tested the role of the gene encoding the D2 dopamine receptor (TaqI A1 allele) in the potentially shared vulnerability to alcohol dependence and bipolar disorder. One hundred and twenty-two French (for at least two generations) patients were recruited on the basis of hospital or outpatient files and were interviewed with the DIGS. The A1 allele frequencies were compared between four groups, namely, with bipolar patients and co-morbid alcohol dependence (N = 21), with bipolar patients without alcohol morbidity (N = 31), with alcohol dependence without mood disorder (N = 35) and unaffected controls (N = 35). The Hardy Weinberg equilibrium for the DRD2 Taq1 A1 genotypes was respected for the sample as a whole, and for each subsample. We observed that 42.9% of control subjects have at least one A1 allele, a frequency which is not significantly different from the one observed in the affected sample as a whole (39.1%), neither from patients with alcohol dependence (37.1%), patients with bipolar disorder (48.4%) nor patients with alcohol dependence and bipolar disorder (28.6%). The regression analysis based on the three variables (bipolar disorder, alcohol dependence and interaction between these two disorders) does not explain the presence of the A1 allele of the DRD2 gene. We thus found no evidence for a significant role of the A1 allele of the D2 dopamine receptor gene in the specific association between bipolar disorder and alcohol dependence in our sample.

Adult↗
PubMed2000

Information processing deficits in relatives of manic depressive patients.

BACKGROUND: The importance of genetic factors in the aetiology of manic-depressive illness (MDI) has been repeatedly confirmed and indicators of vulnerability to the illness in families with affective disorders are needed. Abnormal event-related potentials (ERP) may be markers of genetic vulnerability to mental illness. Long latency and low amplitude of P300 have consistently been reported in schizophrenic patients and their relatives. A few studies have also shown P300 deficits in MDI patients, but no ERP study has been performed on their relatives. METHODS: ERPs were recorded during an auditory oddball task in 19 relatives belonging to families with two or more bipolar patients and in controls with no familial or personal history of affective disorders. The relatives were selected as having no affective disorders on a lifetime basis, but eight had an anxiety disorder. RESULTS: In all relatives, a lower P300 amplitude and a longer P300 latency was found, with much longer reaction time and post-N200 duration till button-press than controls. A lack of P300 amplitude dominance in the right hemisphere was also found in relatives in comparison with controls. There also appeared to be a frontal predominance of ERP abnormalities in relatives. CONCLUSION: We report the first evidence of deficits in reaction time and in P300 amplitude and latency, and a lack of P300 right-sided dominance, in relatives of manic-depressive patients. This pattern may constitute an endophenotypic marker of manic-depressive disorder.

Adult↗
PubMed2000

Association between bipolar disorder and monoamine oxidase A gene polymorphisms: results of a multicenter study.

OBJECTIVE: Although genetic factors have been implicated in the etiology of bipolar disorder, no specific gene has been conclusively identified. Given the link between abnormalities in serotonergic neurotransmission and bipolar disorder, a candidate gene association approach was applied to study the involvement of the monoamine oxidase A (MAOA) gene, which codes for a catabolic enzyme of serotonin, in the susceptibility to bipolar disorder. METHOD: In France and Switzerland, 272 patients with bipolar disorder and 122 healthy subjects were typed for three polymorphic markers of the MAOA gene: the MAOA-CA repeat, the MAOA restriction fragment length polymorphism (RFLP), and a repeat directly adjacent to the variable number of tandem repeats (VNTR) locus. RESULTS: A significant difference in the distribution of the alleles for the MAOA-CA repeat was observed between the female bipolar patients and comparison group. CONCLUSIONS: The results obtained in the French and Swiss population confirm findings from two studies conducted in the United Kingdom.

Adult↗
PubMed1999

Decreased serotonin transporter binding in unaffected relatives of manic depressive patients.

BACKGROUND: There are numerous reports of decreased binding to platelet serotonin transporter (5-HTT) in depression, suggesting that it might be considered a trait marker of depression. To further investigate whether reduced 5-HTT function could be an endophenotype in manic depressive illness, we looked for abnormalities of platelet 5-HTT among subjects who are potential carriers of genetic vulnerability to manic depressive illness (MDI). METHODS: Blood samples were obtained from 20 unaffected relatives from families with at least two individuals with bipolar disorder and from 19 control participants. Plasma 5-HIAA, platelet 5-HT, and [3H] imipramine binding were measured. RESULTS: Unaffected relatives manifested lower platelet 5-HTT function than control participants as revealed both by reduced number and diminished affinity of imipramine binding sites and diminished platelet 5-HT content. CONCLUSIONS: These preliminary results suggest that reduced 5-HTT function could be considered a trait marker or an endophenotype in MDI.

Adrenergic Uptake Inhibitors↗
PubMed1999

Neuropsychological profiles of FMR-1 premutation and full-mutation carrier females

The present French-German investigation of fragile-X syndrome (fra-X) was undertaken to disentangle genetic from environmental effects on cognitive performance as assessed with the following measures: Wechsler Adult Intelligence Scale-Revised (WAIS-R), Wisconsin Card Sorting Test, Trail-Making Test, Tower of Hanai, Verbal Fluency Test, Stroop Test, short-term and consolidation memory, and the d2 task. Groups with different genotypes (n = 11 mothers with a full mutation in the FMR-1 gene of fra-X children; n = 65 mothers with a premutation in the FMR-1 gene of fra-X children; n = 18 siblings of these mothers with normal CGG repeats) and with different psychosocial stressors from fra-X families (n = 14 siblings with a premutation but without affected children of their own) were examined. A group of mothers of non-fra-X autistic children (n = 39) formed an external control group. Previous findings were replicated concerning cognitive performance of FMR-1 full-mutation carrier mothers, who were characterized by lower overall IQ and poorer performance than the group of mothers with the FMR-1 premutation in verbal and performance subtests of the WAIS-R, tests of executive-frontal lobe functioning, and tests of sustained attention. Carriers of the FMR-1 premutation, whether they were mothers of affected children or not,performed in a similar way on all neuropsychological tasks to the intrafamilial control group without CGG amplification. On the basis of these results, it is concluded that there is no neuropsychological evidence of reduced cognitive performance of FMR-1 premutation carriers compared with performance of two control groups with normal CGG repeats. Furthermore, the psychosocial burden of raising fra-X children does not exert an environmental effect on neuropsychological test performance.

Journal Article↗
PubMed1999

Whole blood serotonin and plasma beta-endorphin in autistic probands and their first-degree relatives.

BACKGROUND: Whole blood serotonin (5-HT) and C-terminally directed beta-endorphin protein immunoreactivity (C-ter-beta-EP-ir) are known to be elevated in autistic subjects and might be possible markers of genetic liability to autism. This study thus investigates the familial aggregation of 5-HT and of C-ter-beta-EP-ir levels in first degree relatives of autistic probands. METHODS: In a sample of 62 autistic subjects and 122 of their first-degree relatives, compared to age and sex-matched controls, we measured 5-HT by radioenzymology and C-ter-beta-EP-ir by radioimmunoassay. RESULTS: We confirm the previously reported familiality of hyperserotoninemia in autism as mothers (51%), fathers (45%) and siblings (87%) have elevated levels of 5-HT, and we reveal presence of elevated levels of C-ter-beta-EP-ir in mothers (53%) of autistic subjects. CONCLUSIONS: Familial aggregation of quantitative variables, such as concentration of neurotransmitters, within unaffected relative could serve as an intermediate phenotype and might thus help the search of genetic susceptibility factors in autism.

Adolescent↗
PubMed1999

Temperament in bipolar illness: impact on prognosis.

OBJECTIVE: The present study was designed to investigate the relations between temperament and outcome in bipolar illness. METHODS: Seventy-two patients presenting with bipolar type I disorder were recruited from consecutive admissions and evaluated when euthymic. The criteria developed by Akiskal and Mallya (Criteria for the 'soft' bipolar spectrum: treatment implications. Psychopharmacol. Bull. 1987;23:68-73) were used to assess both depressive (DT) and hyperthymic temperaments (HT) in a dimensional approach. RESULTS: Multiple regression analysis showed that a higher DT score or a lower HT score were significantly associated with a greater number of episodes. Furthermore, a higher DT score was strongly associated with a higher percentage of major depressive episodes. Conversely, a higher HT score was associated with a trend to manic rather than depressive episodes. Suicide attempts appeared more frequent in the history of patients presenting with higher DT scores. CONCLUSIONS: Our findings strengthen the hypothesis that temperament is one of the main variables accounting for some features in the clinical evolution of bipolar disorder such as polarity of episodes. Furthermore, these findings are consistent with the hypothesis of a trait-state continuum between personality and affective episodes.

Adult↗
PubMed1999

Decreased platelet serotonin transporter sites and increased platelet inositol triphosphate levels in patients with unipolar depression: effects of clomipramine and fluoxetine.

BACKGROUND: The central serotonergic system has been implicated in the pathophysiology of depression and in the mechanism of the action of antidepressant drugs. The human platelet has been proposed as a peripheral model of central serotonergic neurons. METHODS: Six peripheral serotonergic parameters were determined simultaneously in 27 patients with unipolar depression before and after 2, 4, and 12 weeks of clomipramine or fluoxetine treatment according to the psychiatrist. RESULTS: In patients with depression versus matched control subjects, platelet [3H]paroxetine binding sites were found to be significantly decreased (2.10 +/- 0.70 versus 3.88 +/- 0.77 fmol/10(9) platelets; P = .0001), platelet serotonin (5-HT) content was found to be significantly decreased (1.90 +/- 1.52 versus 2.74 +/- 1.12 nmol/10(9) platelets; P = .001), and platelet inositol triphosphate levels were found to be significantly increased (2.85 +/- 0.70 versus 1.85 +/- 0.77 fmol/10(9) platelets; P = .0001). No significant difference between patients and control subjects was found for platelet [3H]-lysergic acid diethylamide ([3H]LSD) binding sites, aggregation tests with 5-HT or adenosine diphosphate and plasma 5-HT levels. Treatment with both clomipramine and fluoxetine gradually further reduced the density of platelet [3H]paroxetine binding sites and induced a dramatic decrease in platelet and plasma 5-HT levels. With clomipramine, the decreased blood 5-HT levels are associated with increased platelet [3H]LSD binding sites and aggregation responses. After 12 weeks, nonresponders to both treatments had platelet inositol triphosphate levels that were still increased (2.81 +/- 0.75 fmol/10(9) platelets) when responders levels were not different from those of control subjects (1.41 +/- 0.45 versus 1.70 +/- 0.25 fmol/10(9) platelets). CONCLUSIONS: Drug-free patients with depression had simultaneously decreased 5-HT transporter (5-HTT) sites and overstimulated phosphoinositide signaling systems. Clomipramine and fluoxetine treatments, which further decreased the density of 5-HTT sites, allowed platelet inositol triphosphate levels to return to normal values only in responders.

Adult↗
PubMed1999

Genome-wide scan for autism susceptibility genes. Paris Autism Research International Sibpair Study.

Family and twin studies have suggested a genetic component in autism. We performed a genome-wide screen with 264 microsatellites markers in 51 multiplex families, using non-parametric linkage methods. Families were recruited by a collaborative group including clinicians from Sweden, France, Norway, the USA, Italy, Austria and Belgium. Using two-point and multipoint affected sib-pair analyses, 11 regions gave nominal P -values of 0.05 or lower. Four of these regions overlapped with regions on chromosomes 2q, 7q, 16p and 19p identified by the first genome-wide scan of autism performed by the International Molecular Genetic Study of Autism Consortium. Another of our potential susceptibility regions overlapped with the 15q11-q13 region identified in previous candidate gene studies. Our study revealed six additional regions on chromosomes 4q, 5p, 6q, 10q, 18q and Xp. We found that the most significant multipoint linkage was close to marker D6S283 (maximum lod score = 2.23, P = 0.0013).

Adolescent↗
PubMed1999

Towards a cognitive phenotype for autism: increased prevalence of executive dysfunction and superior spatial span amongst siblings of children with autism.

Two studies were conducted to examine executive function skills in siblings of children with autism. In Study 1, four computerised tasks (three executive tasks: the ID/ED set-shifting task; a spatial working memory task; and the Tower of London planning task; and a control spatial span task) from the CANTAB battery were used to compare 31 siblings of children with autism with 32 siblings of children with developmental delay and 32 children from unaffected families. In Study 2, the two sibling groups were compared on two manually administered executive tasks (verbal fluency and list recall). As a group, autism siblings showed superior spatial and verbal span, but a greater than expected number performed poorly on the set-shifting, planning, and verbal fluency tasks. There were no group differences in working memory performance. The implications of these findings for the broader phenotype of autism is discussed.

Adolescent↗
PubMed1998

Age at onset and gender resemblance in bipolar siblings.

In order to measure the intrafamilial correlation for age at onset and to examine gender resemblance among bipolar siblings, we assessed a sample of 130 bipolar patients belonging to 59 multiple affected sibships. To study the intrafamilial resemblance for age at onset and gender, we used the intraclass correlation and the sibship method, respectively. Within the whole sample, age at onset for affected siblings was correlated (rho = 0.42, P = 0.0001). Gender was randomly distributed among bipolar sibships, demonstrating the absence of gender resemblance among affected siblings. The existence of an intrafamilial correlation for age at onset among bipolar siblings suggests that this variable may assist in the identification of more heritable forms of the illness. No intrafamilial correlation was found for the gender of affected siblings, suggesting that familial vulnerability factors are not gender-specific.

Adolescent↗
PubMed1998

Serotonin transporter gene polymorphisms in patients with unipolar or bipolar depression.

To explore the involvement of serotonin transporter (5HTT) in mood disorder, we studied two polymorphisms of the 5HTT gene (a variable number of tandem repeats in the second intron (VNTR) and a 44 bp insertion/deletion in the 5HTT linked polymorphic region (5-HTTLPR)) in a sample of unipolar and bipolar patients and controls. Homozygosity for the short variant of the 5-HTTLPR was significantly more frequent in bipolar patients than in controls (chi2 = 4.68, d.f. = 1, P = 0.03) whereas there was no difference between bipolar patients and controls for allele distribution, suggesting a recessive effect. The interaction between the two markers suggests that the two polymorphisms probably have independent effects to determine the susceptibility to affective disorder. Further studies are required to identify the precise phenotype associated with 5HTT polymorphisms in depressed patients.

Adult↗
PubMed1998

No association between dopamine D1, D2, and D3 receptor genes and manic-depressive illness.

BACKGROUND: The dopaminergic receptor genes are candidate genes for manic-depressive illness (MDI). To test this putative involvement we used a case-control study on samples from the native population of the northwest part of France. METHODS: Fifty patients for D1 and D2, 61 patients for D3, and 86-223 controls were tested. RESULTS: No significant association was found between allelic frequencies or genotype counts and MDI, even when the data were pooled with those from published studies. CONCLUSIONS: Single mutations of either of the studied receptor genes are not major determinants of MDI.

Adult↗
PubMed1998

Genotype-phenotype relationship in female carriers of the premutation and full mutation of FMR-1.

The present French-German cooperative study focuses on the genotype-phenotype relationship of mutations of the FMR-1 gene and psychiatric conditions in mothers with a full mutation in the FMR-1 gene of fra-X children (n=13), mothers with a premutation in the FMR-1 gene of fra-X children (n=61), as well as premutated siblings of these mothers without affected children (n=17) and two non-mutated control groups: (1) siblings of these mothers with normal CGG repeat (n=18); and (2) mothers of non-fra-X autistic children (n=42). Mothers with a full mutation in the FMR-1 gene and mothers with a premutation in the FMR-1 gene did not differ in the frequency of any axis I disorder; however, both groups were diagnosed with social phobia more often than the control group of mothers of autistic children. Moreover, mothers with a premutation in the FMR-1 gene of fra-X children and their siblings with the premutation (without affected offspring) revealed a similar frequency of social phobia. Furthermore avoidant personality disorder was more common in groups of carriers of the full premutation than in siblings without mutation or than the control group of mothers with autistic children. On the basis of our data, we therefore suggest that social avoidance (expressed as social phobia or avoidant personality disorder) has been underestimated in previous studies of carriers with the FMR-1 full mutation or premutation. Comorbidity of axis I and axis II psychiatric diagnoses was mainly restricted to the group of carriers of the full mutation and carriers of the premutation of FMR-1. Correlations between size of CGG repeat and IQ as well as CGG and age of onset of axis I diagnosis were non-significant. IQ of subjects had no impact on presence or absence of axis I and/or axis II diagnoses.

Adult↗