Association of the serotonin transporter gene-linked polymorphic region (5-HTTLPR) genotype with depression in elderly persons after hip fracture.

OBJECTIVE: The authors examined the serotonin transporter gene-linked polymorphic region (5-HTTLPR) as a predictor of major depressive disorder and depressive symptoms after hip fracture, a common stressful medical event. METHODS: This was a prospective, observational study of 23 elderly rehabilitation-hospital patients during their inpatient stay. Depressive symptoms were assessed by Hamilton Rating Scale for Depression (Ham-D) and PRIME-MD. Subjects were also genotyped for 5-HTTLPR. RESULTS: Survival analysis showed that genotype significantly predicted time-to-major depressive episode. Subjects with an s allele (genotype s/l or s/s) had significantly higher Ham-D scores over 14 weeks of follow-up than those with the l/l genotype. CONCLUSION: Depressive symptoms and major depressive disorder in elderly persons after a stressful medical event may be associated with 5-HTTLPR genotype. This finding requires confirmation in a larger sample.     

Interaction between serotonin transporter gene-linked polymorphic region (5-HTTLPR) and job-related stress in insomnia: a cross-sectional study in Sichuan,China

Objective

Insomnia, a widely occurring sleep disorder in modern society, has a large impact on life quality and work safety. A cross-sectional study was conducted to explore the possible link between serotonin transporter-linked polymorphic region (5-HTTLPR), job-related stress, and insomnia in West China.

Methods

Of the total 462 workers recruited, 177 had insomnia according to the Athens Insomnia Scale (AIS-5). The 5-HTTLPR genotypes were determined by polymerase chain reaction. Job-related stress was assessed for each participant by the General Job Stress Questionnaire.

Results

Unconditional logistic regression models showed that the 5-HTTLPR genotype was significantly associated with insomnia, and >80% increased risk per S allele was observed. High job-related stress had a higher risk for insomnia than low job-related stress (odds ratio [OR], 6.14; 95% confidence interval [CI], 3.94–9.59). Crossover analysis found significant job-related stress × 5-HTTLPR interaction. Compared to individuals with both low job-related stress and SL/LL genotype, those with both higher job-related stress and SS genotype had a higher risk of insomnia (OR, 5.16; 95% CI, 3.13–8.54), whereas those with both low job-related stress and SS genotype showed a lower risk of insomnia (OR, 0.26; 95% CI, 0.08–0.74). The interaction remained statistically significant after adjusting for potential confounding factors.

Conclusions

The findings indicated that 5-HTTLPR could modify the effect of job-related stress on employees' insomnia, suggesting that a work environment-based personalized intervention may be applied to prevent employees' insomnia by alleviating job-related stress in the workplace.     

Influence of the serotonin transporter gene-linked polymorphic region on the antidepressant response to fluvoxamine in Japanese depressed patients

The presence of the long (l) variant of the serotonin (5-hydroxytryptamine: 5-HT) transporter gene-linked polymorphic region (5-HTTLPR) is reported to be associated with a more favorable and faster antidepressant effect of selective serotonin reuptake inhibitors in Caucasians. The frequency of the l allele is lower in Japanese than in Caucasians; therefore, the antidepressant effect of fluvoxamine can be not as good in Japanese as in Caucasians. The authors investigated whether 5-HTTLPR was associated with the antidepressant response to fluvoxamine in 66 Japanese patients with major depressive disorder in a protocolized-dosing 6-week study. The short (s) allele frequency was significantly higher in the responsive individuals than in the nonresponsive ones (P = .010). The present study suggests that fluvoxamine is not less effective in depressive patients carrying the s allele than in the ones carrying the l allele and it is not less effective in Japanese than in Caucasians.     

5-羟色胺转运体基因LPR及5-羟色胺1A受体C(-1019)G基因多态性的联合作用与重性抑郁症的关联研究

目的探讨5-羟色胺转运体基因LPR(5-HTT LPR)多态性和5-羟色胺1A受体(5-HT_(1A)R)C(-1019)G基因多态性的联合作用与重性抑郁症的关系。方法采用病例对照研究,以2005年10月-2007年5月在山西医科大学第一医院就诊的197例重性抑郁症患者为患者组,选取同期该院体检中心与患者组性别、年龄匹配的健康对照者197例为对照组。应用聚合酶链反应技术(PCR)、SDS-聚丙烯酰胺凝胶电泳(SDS-PAGE)及DNA直接测序法对两组的5-HTT LPR及5-HT_(1A)R C(-1019)G基因多态性进行检测。应用UNPHASED软件进行统计分析。结果患者组与对照组的5-HTT LPR和5-HT_(1A)R C(-1019)G多态性位点基因型及等位基因分布频率差异均无统计学意义(P均0.05)。多态性联合作用分析显示,患者组G-S等位基因组合频率高于对照组,差异有统计学意义(21.4%vs.12.4%,P=0.022)。结论在中国汉族人群中,5-HTT LPR和5-HT_(1A)R C(-1019)G的联合作用与重性抑郁症存在关联,G-S等位基因组合可能会增加重性抑郁症发病的危险性。     

A serotonin transporter gene promoter polymorphism (5-HTTLPR) and prefrontal cortical binding in major depression and suicide

BACKGROUND: Major depression and suicide are associated with fewer serotonin transporter (5-HTT) sites. The 5'-flanking promoter region of the 5-HTT gene has a biallelic insertion/deletion (5-HTTLPR). We assayed prefrontal cortical (PFC) 5-HTT binding in major depression and suicide and examine the relationship to the 5-HTTLPR allele. METHODS: Postmortem brain samples from 220 individuals were genotyped for the 5-HTTLPR polymorphism. Binding of 5-HTT was assayed by quantitative autoradiography in the PFC of a subset of subjects (n = 159). Clinical information, including DSM-III-R Axis I diagnoses, was obtained by psychological autopsy and medical chart review. RESULTS: Binding to 5-HTT was lower in the ventral PFC of suicides compared with nonsuicides and was lower throughout the PFC of subjects with a history of major depression. The 5-HTTLPR genotype was associated with major depression but not with suicide or 5-HTT binding. CONCLUSIONS: A diffuse reduction of 5-HTT binding in the PFC of individuals with major depression may reflect a widespread impairment of serotonergic function consistent with the range of psychopathologic features in major depression. The localized reduction in 5-HTT binding in the ventral PFC of suicides may reflect reduced serotonin input to that brain region, underlying the predisposition to act on suicidal thoughts. The 5-HTTLPR genotype was not related to the level of 5-HTT binding and does not explain why 5-HTT binding is lower in major depression or suicide. Arch Gen Psychiatry. 2000;57:729-738     

Simultaneous genotyping of multiple polymorphisms in human serotonin transporter gene and detection of novel allelic variants

The serotonin transporter, called SLC6A4, SERT or 5-HTT, modulates neurotransmission by removal of serotonin from the synapse of serotonergic neurons, facilitating serotonin reuptake into the presynaptic terminus. Selective serotonin reuptake inhibitors block the action of the serotonin transporter and are used to treat depression and other neuropsychiatric disorders. Three polymorphisms in the 5-HTT gene have been implicated in treatment response and neuropsychiatric disorders. A 44-bp promoter ins/del polymorphism (5-HTTLPR) produces primarily long and/or short alleles due to either 14 (short) or 16 (long) repeats of variably conserved 20–23 bp units. Also implicated, a 17–18 bp variable number tandem repeat found in intron2 (StIn2) is expressed as triallelic content with 9, 10, or 12 repeats (StIn2.9, StIn2.10 or StIn2.12). Finally, a single nucleotide polymorphism rs25531 located within the promoter polymorphic-linked region alters the function of the long promoter allele. We developed a PCR-based fragment analysis assay, which is analyzed on an ABI sequencer, whereby we are able to detect all three genotypes simultaneously. Using this technique, we identified novel sequences, which demonstrate promoter repeat regions containing (1) a 17 repeat with rs25531 A/G polymorphism, (2) two with 18-repeat units, (3) one with 20-repeat units and (4) a 24-repeat sequence. The novel repeats were confirmed by direct sequencing of gel-purified amplicons.     

Panic disorder is associated with the serotonin transporter gene (SLC6A4) but not the promoter region (5-HTTLPR)

Panic disorder (PD) and social anxiety disorder (SAD) are moderately heritable anxiety disorders. We analyzed five genes, derived from pharmacological or translational mouse models, in a new case-control study of PD and SAD in European Americans: (1) the serotonin transporter (SLC6A4), (2) the serotonin receptor 1A, (3) catechol-O-methyltransferase, (4) a regulator of g-protein signaling and (5) the gastrin-releasing peptide receptor. Cases were interviewed using the schedule for affective disorders and schizophrenia and were required to have a probable or definite lifetime diagnosis of PD (N=179), SAD (161) or both (140), with first onset by age 31 and a family history of anxiety. Final diagnoses were determined using the best estimate procedure, blind to genotyping data. Controls were obtained from the National Institute of Mental Health Human Genetics Initiative; only subjects above 25 years of age who screened negative for all psychiatric symptoms were included (N=470). A total of 45 single nucleotide polymorphisms were successfully genotyped over the five selected genes using Applied Biosystems SNPlex protocol. SLC6A4 provided strong and consistent evidence of association with the PD and PD+SAD groups, with the most significant association in both groups being at rs140701 (chi(2)=10.72, P=0.001 with PD and chi(2)=8.59, P=0.003 in the PD+SAD group). This association remained significant after multiple test correction. Those carrying at least one copy of the haplotype A-A-G constructed from rs3794808, rs140701 and rs4583306 have 1.7 times the odds of PD than those without the haplotype (95% confidence interval: 1.2-2.3). The SAD only group did not provide evidence of association, suggesting a PD-driven association. The findings remained after adjustment for age and sex, and there was no evidence that the association was due to population stratification. The promoter region of the gene, 5-HTTLPR, did not provide any evidence of association, regardless of whether analyzed as a triallelic or biallelic locus, nor did any of the other four candidate genes tested. Our findings suggest that the serotonin transporter gene may play a role in PD; however, the findings require replication. Future studies should attend to the entire genetic region rather than the promoter.     

Social adversity, the serotonin transporter (5-HTTLPR) polymorphism and major depressive disorder.

BACKGROUND: Recent evidence has suggested that the short allele of the serotonin transporter (5-HTT) gene-linked polymorphic region (5-HTTLPR of the human serotonin gene [SLC6A4]) is associated with increased risk of depressive disorder but only among individuals exposed to social adversity. We report an investigation designed to replicate this finding. METHODS: Data were available from a non-clinical sample of 4,175 adult men and women, ages 41-80 years, selected from participants in the European Prospective Investigation into Cancer and Nutrition in Norfolk (EPIC-Norfolk, United Kingdom) study. Evidence of past-year prevalent episodic major depressive disorder (MDD), defined by restricted DSM-IV diagnostic criteria, was assessed through questionnaire. Adverse experiences in childhood and in adulthood (during the five years preceding assessment) were also assessed through self-report. The 5-HTTLPR variant was genotyped according to published protocols. RESULTS: One-year prevalent MDD criteria were met by 298 study participants. The experience of social adversity (both in childhood and adulthood) was strongly associated with increased rates of past-year prevalent MDD. No gene by environment (GxE) interactions between the 5-HTTLPR genotype, social adversity, and MDD were observed. CONCLUSIONS: This study has not replicated a previous finding of a GxE interaction between the 5-HTTLPR genotype, social adversity, and depression.     

A meta-analysis of the association between the serotonin transporter gene polymorphism (5-HTTLPR) and trait anxiety

Studies of the association between polymorphisms of the serotonin transporter gene (5-HTT) and trait anxiety have produced inconsistent results, raising questions about the strength of the relationship and the methodological conditions under which the relationship holds. We conducted a meta-analysis of existing studies to provide formal statistical measures of the strength of the linked polymorphic region of the serotonin transporter gene (5-HTTLPR)-anxiety relationship. For the entire collection of 26 studies, results provided no support for a relationship between anxiety and the presence of the short form of the 5-HTTLPR polymorphism. There was strong evidence of the presence of moderating variables, however, and subsequent analysis revealed that choice of the measure of trait anxiety was significant. Studies using the Neuroticism scale of Costa and McCrae were found to produce a small positive effect (d=0.23). Other potential moderators (country of study origin, type of subject) did not have a meaningful impact on d statistics. These findings indicate that 5-HTTLPR may in fact have a small but reliable influence on personality, particularly in the manifestation of trait anxiety when measured with a neuroticism scale based on the five-factor model of personality. Our results suggest that the success of future personality genetics research will be maximized by the use of personality measures from both the psychobiological and five-factor models.     

Association of a triallelic serotonin transporter gene promoter region (5-HTTLPR) polymorphism with stressful life events and severity of depression

OBJECTIVE: The lower expressing allele of the serotonin transporter gene 5' promoter region (5-HTTLPR) polymorphism is reported to be associated with susceptibility to depression and suicidality in response to stressful life events. The authors examined the relationship of a triallelic 5-HTTLPR polymorphism to stressful life events, severity of major depression, and suicidality. METHOD: Mood disorder subjects (N=191) and healthy volunteers (N=125), all Caucasian subjects of European origin, were genotyped for the triallelic 5-HTTLPR polymorphism (higher expressing allele: L(A); lower expressing alleles: L(G), S). All subjects underwent structured clinical interviews to determine DSM-IV diagnoses, ratings of psychopathology, stressful life events, developmental history, and suicidal behavior. CSF 5-HIAA was assayed in a subgroup of subjects. RESULTS: Lower expressing alleles independently predicted greater depression severity and predicted greater severity of major depression with moderate to severe life events compared with the higher expressing L(A) allele. No associations with suicidal behavior and CSF 5-HIAA were found. CONCLUSIONS: Lower expressing transporter alleles, directly and by increasing the impact of stressful life events on severity, explain 31% of the variance in major depression severity. The biological phenotype responsible for these effects remains to be elucidated.     

Meta-analysis of serotonin transporter gene promoter polymorphism (5-HTTLPR) association with selective serotonin reuptake inhibitor efficacy in depressed patients

The serotonin transporter gene promoter polymorphism (5-HTTLPR) has been repeatedly associated with antidepressant response in mood disorder patients, but findings are not consistent across studies. A meta-analysis was performed on 15 studies including data of 1435 subjects. We tested three phenotypes: remission rate, response rate and response rate within 4 weeks using the cochrane review manager. We observed a significant association of the s/s variant of 5-HTTLPR with remission rate (P<0.0001) and both s/s and s/l variants with response rate (P=0.0002). Response rate within 4 weeks was associated in both models (P=0.003-P<0.00001). This effect is quite robust to ethnic differences although a significant heterogeneity is present in Asian samples.     

Support for allelic association of a polymorphic site in the promoter region of the serotonin transporter gene with risk for alcohol dependence

OBJECTIVE: An association between the 5-HTTLPR short variant polymorphism in the promoter region of the serotonin transporter gene and risk for alcohol dependence has been reported from case-control studies that are, however, prone to chance findings related to artifacts of population structure. The authors sought additional evidence for this association from a family-based study. METHOD: Ninety-two alcohol-dependent probands and their parents were tested for nonrandom transmission of alleles from heterozygous parents to affected probands. RESULTS: Preferential transmission of the short allele was found (65 of 102 transmissions from heterozygous parents). CONCLUSIONS: The results suggest allelic association between a variant in the promoter region of the serotonin transporter gene and the risk for alcohol dependence. However, it remains to be seen whether the functional properties of this variant are directly responsible for the increased risk to alcohol dependence.     

How the serotonin transporter 5-HTTLPR polymorphism influences amygdala function: the roles of in vivo serotonin transporter expression and amygdala structure

The serotonin transporter-linked promoter region (5-HTTLPR) polymorphism of the serotonin transporter gene is associated with amygdala response during negative emotion. The aim of this study was to investigate whether this genotype effect on amygdala function is mediated by current serotonin transporter (5-HTT) levels or rather by genetically induced influences during neurodevelopment, shaping brain structure. A total of 54 healthy subjects underwent functional and structural magnetic resonance imaging, [¹¹C]DASB positron emission tomography and 5-HTTLPR genotyping to analyze the interrelationships between amygdala activation during processing of unpleasant stimuli, 5-HTTLPR genotype, amygdala volumes and 5-HTT levels in the midbrain and in other brain regions. In line with previous research, carriers of the short allele (S) showed increased amygdala activation. Path analysis demonstrated that this genotype effect was not procured by current 5-HTT availability but by amygdala structure, with smaller amygdala volumes in the S than in the LL genotype, as well as smaller volumes being associated with increased amygdala activation. Our findings stress the role of genetic effects during neurodevelopment.