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Biomedical subjects

Daniel Souery

Publications and source records attributed to Daniel Souery.

At least 19 recordsLinked to original sources
PubMed2006

Glucocorticoid receptor gene-based SNP analysis in patients with recurrent major depression.

Dysregulation of the hypothalamic-pituitary-adrenal axis, one of the stress-response systems, is one of the key neurobiological features of major depression (MDD). Data supporting the notion that glucocorticoid-mediated feedback inhibition is impaired in MDD come from a multitude of studies demonstrating nonsuppression of cortisol secretion following administration of the synthetic glucocorticoid dexamethasone. We examined whether genetic variations in the glucocorticoid receptor gene (Nuclear Receptor Subfamily 3, Group C, Member 1; NR3C1) could be associated with increased susceptibility for MDD using a whole gene-based association analysis of single nucleotide polymorphisms (SNPs). Four SNPs were identified in NR3C1 and genotyped in two well-diagnosed samples of patients with MDD ascertained in Belgium and northern Sweden, and matched control samples. In total, 314 MDD patients and 354 control individuals were included in the study. In the Belgian sample, we observed significant allele (p=0.02) and genotype (p=0.02) association with an SNP in the promoter region (NR3C1-1); in the Swedish sample, we observed significant allele (p=0.02) and genotype (p=0.02) association with the R23K SNP. The haplotype association studies showed modest evidence for an involvement of the 5' region of the NR3C1 gene in the genetic vulnerability for MDD. This study suggests that polymorphisms in the 5' region of the NR3C1 gene may play a role in the genetic vulnerability for MDD.

Belgium↗
PubMed2006

Shortened onset of action of antidepressants in major depression using acetylsalicylic acid augmentation: a pilot open-label study.

Based on our preclinical data showing a potential accelerating effect of acetylsalicylic acid (ASA) in combination with fluoxetine in an animal model of depression, we examined the effect of ASA augmentation therapy on selective reuptake inhibitors (SSRI) in major depressed non-responder patients. Twenty-four non-responder patients having received at least 4 weeks of an adequate SSRI treatment were included in a pilot open-label study. Participants were treated openly during 4 weeks with 160 mg/day ASA in addition to their current antidepressant treatment. The combination SSRI-ASA was associated with a response rate of 52.4%. Remission was achieved in 43% of the total sample and 82% of the responder sample. In the responder group, a significant improvement was observed within week 1 (mean Hamilton Depression Rating Scale-21 items at day 0=29.3+/-4.5, at day 7=14.0+/-4.1; P<0.0001) and remained sustained until day 28. Despite limitations due to the open nature of this study, our preliminary results confirm our preclinical findings and are in favour of an accelerating effect of ASA in combination with SSRIs in the treatment of major depression. Potential physiological and biochemical mechanisms may involve an anti-inflammatory and/or neurotrophic effect.

Adult↗
PubMed2006

Lack of genetic association between the phospholipase A2 gene and bipolar mood disorder in a European multicentre case-control study.

The possible association between phospholipase A2 gene and bipolar mood disorder was examined in 557 bipolar patients and 725 controls (all personally interviewed), recruited from seven countries (Belgium, Bulgaria, Croatia, Germany, Greece, Italy, and UK). The frequencies of the eight alleles that were identified did not differ between patients and control individuals in the whole population, while the power to detect an association based on our sample was relatively high. Some differences were noted among the various ethnic groups, but no significant trends existed, suggesting that population stratification by country may not be responsible for a type II error. On the basis of these results, mutations of the phospholipase A2 gene, at least in the region close to the polymorphism examined between exons 1 and 2, are not involved in the pathogenesis of bipolar mood disorder.

Base Pairing↗
PubMed2006

Treatment-resistant depression.

Treatment-resistant depression (TRD) is a common clinical occurrence among patients treated for major depressive disorder. However, a clear consensus regarding the criteria defining TRD is lacking in the psychiatric community. Many patients who are considered treatment resistant are actually mis-diagnosed or inadequately treated. Clinicians need to accurately diagnose TRD by examining primary and secondary (organic) causes of depression and acknowledging paradigm failures that contribute to a misdiagnosis of TRD. A correct determination of what constitutes TRD requires consensus on criteria of treatment response (i.e., dose, duration, and compliance) and on the number of adequate trials required before a patient is determined to be nonresponsive. Additionally, clinical validation of available staging models needs to be completed. While several studies have identified predictors of non-response, clinical studies investigating the predictors of resistance following the failure of 2 or more antidepressant trials should be pursued. In managing TRD, 3 pharmacotherapy strategies are in clinical use: optimization of antidepressant dose, augmentation/combination therapies, and switching therapies. However, the optimal strategy for treating TRD has yet to be identified. Therefore, further controlled clinical trials are essential to identify the most effective treatment strategies.

Antidepressive Agents↗
PubMed2006

Consensus statement and research needs: the role of dopamine and norepinephrine in depression and antidepressant treatment.

During a special session, the faculty identified several specific areas related to the role of dopamine and norepinephrine in depression and antidepressant treatment that either warrant the clinician's attention or are in need of more research. Areas of interest include fatigue and lethargy in depression, treatment strategies for treatment-resistant depression, the somatic presentation of depression, neurobiology of fatigue and its role in determining treatment, symptom rating scales, and sexual side effects. In addition, the faculty discussed the importance of patient psychoeducation and self-management as well as the ways in which disease models of depression affect treatment.

Antidepressive Agents↗
PubMed2005

Patient-control association study of substance P-related genes in unipolar and bipolar affective disorders.

In the search of genes potentially implicated in the aetiology of affective disorders (AD), SUBSTANCE P (SP) pathway is receiving increased interest. SP receptor antagonists, such as MK-869 and L-759274, have been shown to have antidepressant effect. Results from preclinical and human studies implicate SP and its pathway in the pathophysiology of mood disorders. We investigated a possible association between 20 single nucleotide polymorphisms (SNPS) among four SP-related genes and unipolar and bipolar ad (UPAD and BPAD) in a first sample of 92 UPAD patients and 92 control individuals and in a replication sample of 92 UPAD patients and 92 control individuals. An additional sample of 113 BPAD patients has also been ascertained. Our results showed a significant association between the angiotensin-converting enzyme gene (ACE1) and UPAD in our first sample, but not in the replication sample. No significant evidence of association was found in other SP-related genes. We did not find any association in the BPAD sample. When pooling first and replication UPAD samples, an association was found between ACE1 and a subgroup of patients remaining depressed after an adequate antidepressant treatment. In conclusion, our findings do not support a major contribution of SP-related genes in UPAD and BPAD, but provides some evidence of an ace influence in treatment response to antidepressants.

Adult↗
PubMed2005

No implication of brain-derived neurotrophic factor (BDNF) gene in unipolar affective disorder: evidence from Belgian first and replication patient-control studies.

Several lines of evidence have suggested an implication of brain-derived neurotrophic factor (BDNF) in unipolar affective disorder (UPAD). In the present study, we investigated the role of BDNF gene in UPAD in two independent samples of 92 patients/92 controls and 156 patients/197 controls. Two single nucleotide polymorphisms (SNPs) were investigated. We found no significant differences of BDNF gene SNPs distribution between UPAD patients and controls in both samples. Haplotype analyses were performed on both samples. A statistical difference was found between cases and controls in the first sample but not in the second. These results are not in favour of an implication of BDNF in UPAD but need to be replicated before final conclusion.

Adult↗
PubMed2004

Non-replication of the brain-derived neurotrophic factor (BDNF) association in bipolar affective disorder: a Belgian patient-control study.

This patient-control association study was conducted to investigate a possible association of two single nucleotide polymorphisms (SNPs), g.11757C > G and g.196G > A, in the brain-derived neurotrophic factor (BDNF) with bipolar affective disorder (BPAD). Two hundred seventy-five individuals of Belgian origin (at least two generations of Belgian ancestors) were genotyped (112 BPAD and 163 controls). No significant differences were found in the frequency of genotypes and alleles of g.196G > A (P = 0.37 and 0.94, respectively) and g.11757C > G (P = 0.49 and 0.59, respectively) between controls and BPAD patients. An haplotype analysis revealed no difference between patients and controls (P = 0.44). We failed to replicate previous findings implicating BDNF in the aetiology of BPAD. However, BDNF remains an interesting target for future genetic studies and should be tested in prospective pharmacogenetic therapeutic trials.

Adult↗
PubMed2004

Expanded RED products and loci containing CAG/CTG repeats on chromosome 17 (ERDA1) and chromosome 18 (CTG18.1) in trans-generational pairs with bipolar affective disorder.

The purpose of the present study was to further test if expanded CAG repeats detected by the repeat expansion detection (RED) method in bipolar affective disorder (BPAD) are correlated with ERDA1 (17q21.3) and/or CTG18.1 (18q21.1) loci expansions, and changes of phenotype severity in successive generations (anticipation). The sample was designed to analyze ERDA1 and CTG18.1 expansions in trans-generational pairs of affected individuals (parent-offspring pairs: G1 and G2). Clinical and genetic information was available on 95 two-generations pairs. We found in our sample no one patient carrying an expanded allele at the CTG18.1 locus. This observation is true for all individuals in G1 and G2. Using the conditional logistic regression, no statistical difference was observed between the two generations for ERDA1 alleles (chi(2) = 0.2, P = 0.65). These data do not support the correlation between expanded RED products (RED fragments >120) and expanded alleles at ERDA1 in trans-generational pairs with BPAD. We were not able to detect any correlation for CTG18.1. Earlier age at onset in offspring generation was also not associated with expanded RED products explained by expanded ERDA1 alleles.

Adult↗
PubMed2004

Molecular genetics of affective disorders.

Evidence for familial aggregation in Affective Disorders (AD) has been provided in classical studies. Linkage and association genetic studies have been proposed to detect genetic factors implicated in AD. However, findings from molecular genetic studies remain inconclusive. Nevertheless, current research is focusing on the phenotypes, both sub- and endophenotypes. In addition, recent advances in technology, such as microarrays, provide new tools in psychiatric genetics. These different approaches offer a new optimism era in the search of genetic factors in AD.

Biogenic Monoamines↗
PubMed2004

Serotonin transporter 5HTTLPR polymorphism and affective disorders: no evidence of association in a large European multicenter study.

The available data from preclinical and pharmacological studies on the role of the serotonin transporter (5-HTT) support the hypothesis that a dysfunction in brain serotonergic system activity contributes to the vulnerability to affective disorders (AD). 5-HTT is the major site of serotonin reuptake into the presynaptic neuron, and it has been shown that the polymorphic repeat polymorphism in the 5-HTT promotor region (5-HTTLPR) may affect gene-transcription activity. 5-HTT maps to chromosome 17 at position 17q11.17-q12, and the 5-HTTLPR polymorphisms have been extensively investigated in AD with conflicting results. The present study tested the genetic contribution of the 5-HTTLPR polymorphism in a large European multicenter case-control sample, including 539 unipolar (UPAD), 572 bipolar patients (BPAD), and 821 controls (C). Our European collaboration has led to efforts to optimize a methodology that attenuates some of the major limitations of the case-control association approach. No association was found with primary psychiatric diagnosis (UPAD and BPAD) and with phenotypic traits (family history of AD, suicidal attempt, and presence of psychotic features). Our negative findings are not attributable to the lack of statistical power, and may contribute to clarify the role of 5-HTTLPR polymorphism in AD.

Bipolar Disorder↗
PubMed2003

Lack of association between the 5HT2A receptor polymorphism (T102C) and unipolar affective disorder in a multicentric European study.

We report here a case-control association study with T102C polymorphism in the serotonin 2A receptor gene (HTR2A) in patients affected by unipolar affective disorder (UPAD) and in controls. A total of 284 subjects were genotyped (142 UPAD and 142 controls). All subjects were interviewed using standard diagnostic interviews and matched. A homogenous population of unipolar patients with suicidal attempt was identified. Conditional logistic regression was applied. No association of the HTR2A polymorphism was found in the overall sample of 142 UPAD-control pairs regarding allele and genotype frequencies (P=0.36 and P=0.52 respectively) and homo-heterozygote distributions (P=0.91). This study confirms, in a multicentric European sample, the earlier observations that the T102C HTR2A polymorphism is not associated with UPAD. Nevertheless, a type 2 statistical error cannot be excluded. Therefore, to exclude the implication of HTR2A in UPAD, this result must be replicated in larger samples and in other populations using the transmission disequilibrium test and different polymorphisms around HTR2A.

Case-Control Studies↗
PubMed2003

Molecular genetics of affective disorders.

Family studies have provided evidence for familial transmission in suicide in major psychiatric disorders, and in particular affective disorders. Even though they may seem contradictory, linkage studies have suggested several genetic regions implicated in affective disorders. Association studies have mainly focused on genes related to serotonergic and monoaminergic pathways. Other genes involved in GABAergic and substance P pathways have also been studied in association studies. Another way to approach the genetics of affective disorders is the definition of more detailed phenotypes. Suicidal behaviour is one of the more largely studied subphenotypes within affective disorders. Tryptophan hydroxylase and serotonin transporter genes, related to the serotonergic pathway, have been found to be associated to suicidal behaviour, in particular violent suicidal behaviour but need to be replicated before definitive conclusion. Improved methodologies and updated tools in genetic studies will improve in the future our knowledge of affective disorders.

DNA↗
PubMed2003

Introduction to the Special Section. New advances in the understanding and treatment of bipolar disorder.

The current renewed interest in the field of bipolar disorders can be attributed to various factors which are reviewed in this Special Section of the International Journal of Neuropsychopharmacology. Bipolar disorders are one of the most frequent disorders in psychiatry and this Special Section presents papers on recent advances in the clinical course, epidemiology, biological models and neurobiology of bipolar disorders. Novel therapeutic approaches will be covered in a second part in Volume 6, Number 3 (September 2003).

Adolescent↗
PubMed2003

Molecular genetics in the analysis of suicide.

Each year, one million people die of suicide. Among the different identified risk factors, genetic factors seem to be part of a multidimensional behavior, including psychiatric, psychosocial, biological factors and physical illness. Family studies have provided evidence for familial transmission in suicide, confirmed in twin and adoption studies. At a molecular level, serotonin seems to be one of the key neurotransmitters implicated in suicidal behavior. Therefore, genes coding for proteins involved in serotonergic neurotransmission have been extensively studied in case-control association studies on suicide. Major findings concern Tryptophan hydroxylase (TPH) gene, particularly in violent suicidal behavior. Though they may seem contradictory, studies on Serotonin transporter (5-HTT), Monaomine oxidase (MAOA), Serotonin 2A and 2C receptors (5-HT2A and 5-HT2C) and Tyrosine hydroxylase (TH) genes are promising. In spite of those observations having some limitations, it appears that genetic factors are a serious risk factor, besides environmental aspects of suicidal behavior.

Aged↗
PubMed2003

Noradrenaline in mood and anxiety disorders: basic and clinical studies.

The neurotransmitter noradrenaline is known to be involved in a range of physiological and psychological processes, and dysfunctions of this neurotransmitter system have been implicated in a range of psychiatric disorders. However, the clinical utility of targeting the noradrenergic system in the treatment of such disorders has been somewhat overshadowed by the availability of agents selective for the serotonin system. A number of antidepressants with increased, but varying, selectivity for the noradrenergic system have become available in recent years, including mirtazapine, bupropion and, most recently, the first truly selective noradrenaline reuptake inhibitor, reboxetine. This review brings together current thinking on the role of noradrenaline in the aetiology and therapy of mood disorders to encourage a rational, evidence-based approach to the treatment of such disorders, and to provide suggestions and guidelines for future research in the area.

Animals↗