Serotonin Transporter Gene Polymorphism Research Articles

Dating violence victimization and substance use: The role of a serotonin transporter gene polymorphism (5HTTLPR)

While there is developing research on how genes moderate the effect of stressful life events on substance use, the limited research has yet to focus on specific stressors. As adolescent dating violence victimization has been linked to various substance use behaviors, the current research seeks to further examine the longitudinal outcomes of adolescent dating violence victimization and the role that genes play in moderating these effects. Specifically, using data from the National Longitudinal Study of Adolescent to Adult Health (Add Health), a series of logistic and negative binomial regressions are run to analyze the direct and interactive effects of adolescent dating violence victimization and a polymorphism (5HTTLPR) in the promoter region of the serotonin transporter gene on both alcohol use problems and marijuana use. The results find that 5HTTLPR interacts with adolescent dating violence victimization to increase odds of marijuana use for the sample. However, the interaction between 5HTTLPR and adolescent dating violence has differential effects for males and females, suggesting sex differences regarding the susceptibility properties of 5HTTLPR. Implications of these findings are discussed.

Polymorphism in the serotonin transporter gene polymorphisms (5-HTTLPR) modifies the association between significant life events and depression in people with multiple sclerosis

Background: In the general population, variation in the serotonin-transporter-linked polymorphic region (5-HTTLPR) has been shown to modify the association between stressful events and depression/anxiety. This has not been examined in people with multiple sclerosis (MS). Objective: We examined the interaction between significant life events (SLE), 5-HTTLPR and depression/anxiety. Methods: A population-based longitudinal cohort of 198 people with MS was followed biannually for 2.5 years. Depression and anxiety symptoms were measured at each review using the Hospital Anxiety and Depression Scale (HADS). SLEs were assessed using a questionnaire based on the Social Readjustment Rating Scale. Results: We found an interaction between SLE load in the previous 12 months and functional variation in the 5-HTTLPR allele type in predicting depression, with the association between SLE load and depression being stronger for those with S/S allele type (β = 0.21 (95% confidence interval (CI): 0.09–0.33) per 10-unit increase) and S/L (β = 0.14 (95% CI: 0.05–0.24)) compared to L/L allele type (β = 0.04 (95% CI: −0.05 to 0.24); pinteraction < 0.001). No convincing evidence of an interaction was found with anxiety. Conclusion: We found that the association between SLE load and MS depression severity was stronger among those with one or two copies of the short allele of the 5-HTTLPR. The identification of a gene–environment interaction between SLEs and depression in a population where depression is partly disease-driven is novel.

The Serotonin Transporter Gene Polymorphisms and Risk of Ischemic Stroke

Introduction: Serotonin is known as a neurotransmitter; however, it also plays an important role in platelet aggregation as it is released upon platelet activation. The serotonin transporter (SERT) is responsible for the uptake of serotonin into platelets. Functional polymorphisms in the SERT gene may influence platelet activity, as they result in different levels of transporters and thereby different levels of serotonin in platelets. SERT gene polymorphisms have thus been associated with the risk of myocardial infarction. A similar association may exist between SERT gene polymorphisms and stroke. However, to our knowledge, this potential association has not previously been studied. We therefore aimed to investigate the association between polymorphisms in the SERT gene and the risk of ischemic stroke/transitory ischemic attack (TIA). Materials and Methods: We conducted a case-control study including 834 consecutively admitted first-ever Caucasian ischemic stroke patients/TIA from Aarhus University Hospital, Denmark and 571 healthy controls. The control group comprised a sample from the Danish working population, who were all employees in the public sector in the Central Denmark Region. Two polymorphisms, the length variation (short = S/long = L) in the serotonin-transporter-linked polymorphic region and a single-nucleotide (A/G) polymorphism (rs25531) were studied. The genotypes were grouped according to the functional activity: SS, SLG and LGLG (low expression), SLA, LGLA (medium expression), and LALA (high expression). Data were analyzed using logistic regression and results presented as OR with 95% CI. Results: The high-expression genotype was associated with a lower risk of ischemic stroke/TIA when compared to both the medium expression genotype (OR 0.72, 95% CI 0.56–0.93) and the low-expression genotype (OR 0.75, 95% CI 0.55–1.01) as well as the combination of the low and medium expression genotypes (OR 0.73, 95% CI 0.58–0.93). The lower OR estimates associated with the high-expression genotype were consistent across all stroke subtypes, although not statistically significant. The results remained virtually unchanged, although not reaching statistical significance, when adjusting for age and gender. Conclusion: The presence of the high expression SERT genotype (LALA) may be associated with a lower risk of ischemic stroke/TIA. This is, to our knowledge, the first study examining the SERT gene polymorphisms and the risk of stroke. The present results raise interesting considerations for future personalized medicine potential, and we argue that further larger-scale studies with sufficient power to study subgroups according to stroke etiology and stroke-onset age are needed.

The relation between temporomandibular disorders, mood status and serotonin transporter gene polymorphism. Study in Syrian population.

The purpose of this study was to evaluate the relationship betweentemporomandibular disorders, mood status and serotonin transporter (5-HTT) genepolymorphisms in Syrian population. Twenty patients with temporomandibular jointdisorder (TMD), and 36 healthy control subjects were examined. The sample consistsof 23 males, and 33 females aged between (19-30 years old), visited the department offixed prosthodontic of the faculty of dentistry, Damascus University. This studyshows that S/L allele of 5-HTTLPR was the most frequently observed allele in TMDpatients; whereas statistical analysis did not show significant difference betweenpatient and control groups by neither genotype distribution analysis nor allelefrequency analysis. S\S allele analysis showed a relation between it and mood status.Although the study did not show significant relation between TMD and serotonintransporter polymorphism gene, but according to the importance of serotonintransporter polymorphism gene and its relation to psychological factors we suggestother studies which focus on the relation between the genetics, psychology and TMD.

Polymorphism of serotonin transporter gene (SLC6A4) and its relation to tramadol dependence

Background Many genes have been proven to be linked to substance use disorder, on top were serotonin receptor and transporter genes. Aim The aim of this study was to determine the frequency of 5-HTTVNTR allele variants of the serotonin transporter gene and the presence of polymorphic serotonin receptor gene (5-HTR1A) in tramadol-dependent patients in comparison with controls and to explore the association between the groups of tramadol dependent with and without psychiatric comorbidity and 5-HTTVNTR allele variants. Patients and methods This was a cross-sectional case–control outpatient study. The study sample consisted of 90 patients, with 60 tramadol dependents (55 males and five females) and 30 healthy controls. All patients fulfilled the Diagnostic and Statistical Manual of Mental Disorders, 4th ed., Criteria for substance dependence (on tramadol). Genotyping of the 5-HTTVNTR gene and 5-HT1A receptor gene promoter was done employing real-time PCR and PCR/RFLP, respectively. Results A significant association was found between the 5-HTT gene 10 allele polymorphism and tramadol dependence. No significant association was observed with the 5-HT receptor gene polymorphism. Conclusion This study detected an association between the presence of 5-HTTVNTR less transcriptional-efficient genotypes and tramadol dependence, and these genotypes increase psychiatric comorbidity with tramadol dependence, which suggests that the modulation of the serotoninergic system might be implied in psychiatric problems in tramadol dependence.

Serotonin Transporter Gene Polymorphism in Women With Suspected Ischemia

Introduction: Association of serotonin transporter gene ( 5-HTTLPR) polymorphisms with adverse cardiovascular (CV) events in women with suspected ischemia has not yet been reported. We hypothesized an association of 5-HTTLPR polymorphisms with risk of adverse CV events in women with suspected ischemic heart disease (IHD) referred for coronary angiography enrolled in the Women’s Ischemia Syndrome Evaluation (WISE). Method: We studied clinical and angiographic data and DNA from a cohort of 437 Caucasian women enrolled in the WISE genotyped for the long (L) and short (S) variant of the 5-HTTLPR polymorphism. Women were followed yearly for adverse CV events (defined as first occurrence of all-cause death, myocardial infarction, stroke, or heart failure hospitalization) with data collected at WISE 10-year follow-up. Exploratory analyses compared outcomes between genotype groups. Results: A total of 437 women, with baseline, angiographic, and long-term follow-up data, were successfully genotyped. Their mean age was 58 ± 11 years and body mass index 29 ± 6; 54% had hypertension, 18% diabetes, 50% dyslipidemia, 20% depression history, and only 34% had obstructive CAD. At 8.9 years median follow-up, the SS genotype was associated with significantly increased risk of adverse CV event versus LL + LS (1.93, confidence interval [CI]: 1.03-3.61, P = .03). Results were not significant for all-cause death (hazard ratio: 1.63, CI: 0.91-2.93, P = .09). Conclusion: Among a cohort of Caucasian women with suspected IHD enrolled in the WISE, the SS homozygous genotype for the 5-HTTLPR polymorphism was associated with increased risk of adverse CV outcomes.

A relationship between early life stress and depression: the role of the serotonin transporter gene polymorphism (5-HTTLPR)

A relationship between early life stress and depression: the role of the serotonin transporter gene polymorphism (5-HTTLPR)

Situation Awareness Performance in Healthy Young Adults Is Associated With a Serotonin Transporter Gene Polymorphism.

Background Situation awareness (SA) is defined in three levels: SA1 is the perception of the elements in a specific context, SA2 is the comprehension of their meaning, and SA3 is the projection of their status. Purpose To analyze the possible association of a genetic polymorphism in the serotonin transporter ( SLC6A4) gene and performance on the Situational Awareness test (SAtest). Methods SAtest was applied to a sample of 230 healthy Colombian subjects, using the Psychology Experiment Building Language platform and a functional polymorphism in the SLC6A4 gene was genotyped by polymerase chain reaction. Results In the SA1 level, s/s genotype carriers had worse accuracy, in comparison with s/l and l/l genotypes. At SA2 level, l/l genotype carriers had better accuracy than s/s and s/l individuals and that in the SA3 level, l/l carriers also had better accuracy. These associations were significant after correction for multiple testing. Conclusions It is possible that l/l carriers have a better ability to perceive and focus their attention on the elements of their environment and to have the capacity to understand and predict what will happen with those elements. This is the first genetic study of SA performance in healthy participants. Additional investigations of other genes could contribute to the understanding of the molecular correlates of SA in healthy subjects and in neuropsychiatric patients.

Serotonin transporter gene polymorphisms may be associated with poststroke neurological recovery after escitalopram use

ObjectiveSelective serotonin reuptake inhibitors (SSRIs) putatively improve neurological recovery after stroke. We aimed to investigate whether serotonin transporter (SERT) gene polymorphisms are related to the responsiveness to SSRIs in the...

Evaluation of 5-HTTLPR Gene Polymorphism and Resilience Components on the Development of Psychopathology in Adolescent Sexual Abuse Cases.

More than one-fourth adolescents are exposed to unexpected frightening experiences and traumas until adulthood. In this study, we aimed to determine the potential role of serotonin transporter (5-HTT) gene polymorphism regarding resilience factors in the symptom variability of individuals exposed to sexual abuse. Adolescents aged 11-17 years, who were admitted to the Marmara University Child Psychiatry Outpatient Clinic Forensic division with sexual abuse experience history, were informed about the research, and volunteers were included in the study. Turkish versions of "Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime (K-SADS-PL)" was used to assess the psychopathology and functionality. The evaluation of participants also included self-reports based on "Eysenck Personality Inventory" and "Ways of Coping Inventory" for reflecting the resilience domain. The sample included 16 girls (88.9%) and 2 boys (11.1%), and the mean (±standard deviation) age was 14.58±1.97 years. Genotyping of the insertion/deletion polymorphism (5-HTTLPR) in the 5-HTT gene's transcriptional control zone was established, and 8 participants (44.4%) were determined to be of the LL genotype, while 7 (38.8%) were LS and 3 (16.6%) were SS carriers. Considering the relationship between coping styles regarding resilience and genetic variants, 87.5% of participants (n=7) exhibiting problem-focused coping style were determined found to carry the LL allele, while 90% (n=9) who exhibited emotion-focused coping styles were the SS-LS allele carriers (p=0.003). Our findings suggest that 5-HTTLPR gene polymorphism has a significant impact on the formation of coping styles. More studies are needed to determine other factors involved in the complex relationship between 5-HTTLPR gene polymorphism and development of psychopathology.

Association between serotonin transporter gene polymorphisms and increased suicidal risk among HIV positive patients in Uganda

BackgroundPersons living with HIV/AIDS (PLWHA) are at an increased risk of suicide. Increased suicidal risk is a predictor of future attempted and completed suicides and has been associated with poor quality of life and poor adherence with antiretroviral therapy. Clinical risk factors have low predictive value for suicide, hence the interest in potential neurobiological correlates and specific heritable markers of suicide vulnerability. The serotonin transporter gene has previously been implicated in the aetiology of increased suicidal risk in non-HIV infected study populations and its variations may provide a platform for identifying genetic risk for suicidality among PLWHA. The present cross-sectional study aimed at identifying two common genetic variants of the serotonin transporter gene and their association with increased suicidal risk among human immunodeficiency virus (HIV)-positive adults in Uganda.ResultsThe prevalence of increased suicidal risk (defined as moderate to high risk suicidality on the suicidality module of the Mini Neuropsychiatric Interview (M.I.N.I) was 3.3% (95% CI, 2.0–5.3). The 5-HTTLPR was found to be associated with increased suicidal risk before Bonferroni correction (p-value = 0.0174). A protective effect on increased suicidal risk was found for the 5-HTTLPR/rs25531 SA allele (p-value = 0.0046)- which directs reduced expression of the serotonin transporter gene (5-HTT).ConclusionThe SA allele at the 5-HTTLPR/rs25531 locus is associated with increased suicidal risk among Ugandan PLWHA. Further studies are needed to validate this finding in Ugandan and other sub-Saharan samples.

Association between the serotonin transporter gene polymorphism and verbal learning in older adults is moderated by gender

The S allele of the functional 5-HTTLPR polymorphism has previously been associated with reductions in memory function. Given the change in function of the serotonergic system in older adults, and the functional consequences of memory decline in this age group, further investigation into the impact of 5-HTTLPR in healthy older adults is required. This investigation examined the effect of 5-HTTLPR variants (S carriers versus L/L homozygotes) on verbal and visual episodic memory in 438 healthy older adults participating in the Tasmanian Healthy Brain Project (age range 50–79 years, M=60.35, s.d.=6.75). Direct effects of 5-HTTLPR on memory processes, in addition to indirect effects through interaction with age and gender, were assessed. Although no direct effects of 5-HTTLPR on memory processes were identified, our results indicated that gender significantly moderated the impact that 5-HTTLPR variants exerted on the relationship between age and verbal episodic memory function as assessed by the Rey Auditory Verbal Learning Test. No significant direct or indirect effects were identified in relation to visual memory performance. Overall, this investigation found evidence to suggest that 5-HTTLPR genotype affects the association of age and verbal episodic memory for males and females differently, with the predicted negative effect of S carriage present in males but not females. Such findings indicate a gender-dependent role for 5-HTTLPR in the verbal episodic memory system of healthy older adults.

An exploratory genetic analysis: Associations between parent depression symptoms, child temperament, and the serotonin transporter gene polymorphism (5HTTLPR)

Child temperament has been shown to be biologically based and heritable; however, genetic association studies of temperament have been fairly inconclusive, and the role that parental depressive symptoms play is largely unexplored in this context. The relationship between parent depressive symptoms and the child temperament dimensions of fear and activity level (AL) were examined in 100 sibling pairs 2.5–5.5 years of age and their mothers. Parent reports of child temperament and parent self‐reports of depressive symptoms were obtained from families, as well as DNA samples from each child during their lab visit. Associations between the serotonin transporter gene (SLC6A4) polymorphism 5‐HTTLPR/rs25531 and the phenotypic variables were also explored. Parent depressive symptoms were significantly related to higher child AL, but minimally associated with fear outcomes. More powerful regression analyses revealed that parent depressive symptoms, child gender, and child age predicted child AL, but only child gender and age predicted child fear. In our exploratory candidate gene analyses, the low‐expressing genotypes of the 5‐HTTLPR/rs25531 polymorphism predicted child fearfulness, but not child AL. Our phenotypic findings indicate that a child with at least one parent with depressive symptoms is more likely to have higher AL, and results of the initial genetic analyses show that the 5‐HTTLPR/rs25531 polymorphism is associated with child fearfulness. Future research employing larger samples, observational assessments, and related child behavioral maladjustment measures will further clarify these findings.

The triallelic serotonin transporter gene polymorphism is associated with depressive symptoms in adults with chronic pain.

BackgroundThe serotonin (5-HT) transporter-linked polymorphic region (5-HTTLPR) moderates the relationship between stressful life events and depression. Given the high prevalence of depression in chronic pain, the primary aim of this preliminary study was to investigate the associations between the 5-HTTLPR and the severity of depressive symptoms in a cohort of adults with chronic pain.MethodsAdults with chronic pain who were consecutively admitted to an outpatient pain rehabilitation program and met inclusion criteria were recruited for study participation (n=277). Individuals were genotyped for the 5-HTTLPR (including rs25531) and categorized as high, intermediate, or low expressors of the 5-HT transporter. The severity of depressive symptoms at admission was measured by using the Center for Epidemiologic Depression scale (CES-D).ResultsThe distribution of the high-, intermediate-, and low-expressing genotypes was 61 (22%), 149 (54%), and 67 (24%), respectively. The Hardy–Weinberg P-value was 0.204, which indicated no departure from equilibrium. A main effect of 5-HTTLPR was observed for depressive symptoms (P=0.040) where Center for Epidemiologic Depression scale (CES-D) scores were significantly greater in the low-expressing group compared to the high- (P=0.019) and intermediate (P=0.029)-expressing groups. In multivariate multinomial logistic regression analysis adjusted for age, sex, pain severity, pain catastrophizing, and pain anxiety, greater CES-D scores were significantly associated with the 5-HTTLPR low-expressing group compared to the high-expressing group (P=0.023), but not for the low-expressing group compared to the intermediate-expressing group (P=0.056).ConclusionThese preliminary findings suggest that the triallelic 5-HTTLPR could influence the severity of depressive symptoms in adults with chronic pain. Individuals with chronic pain may be particularly vulnerable to the moderating effects of 5-HTTLPR due to high levels of pain-related stress that are inherently present in this population.

Serotonin Transporter Gene Polymorphisms and Early Parent-Infant Interactions Are Related to Adult Male Heart Rate Response to Female Crying.

Adults' adaptive interactions with intimate partners enhance well-being. Here we hypothesized that adult males' physiological responses to opposite-sex conspecifics' distress result from an interaction between an environmental factor (early social interaction with caregivers) and a genetic factor (a polymorphism within the promoter region of the serotonin transporter gene, 5-HTTLPR). We assessed heart rate changes in 42 non-married male adults to distress vocalizations (female, infant, and bonobo cries). Males' early interaction with parents was assessed using the Parental Bonding Instrument. Buccal mucosa cell samples were collected to assess their 5-HTTLPR genotype. A significant interaction emerged between early experience and genetic predisposition. Males with a genetic predisposition for higher sensitivity to environmental factors showed atypical physiological responses to adult female cries according to their experienced early maternal parenting. Environmental experiences and genetic characteristics are associated with adult males' physiological responses to socially meaningfully stimuli. Understanding the mechanisms that modulate responses to opposite-sex conspecifics may improve personal well-being and social adaptiveness.

Serotonin transporter gene (SLC6A4) polymorphism and susceptibility to a home-visiting maternal-infant attachment intervention delivered by community health workers in South Africa: Reanalysis of a randomized controlled trial.

BackgroundClear recognition of the damaging effects of poverty on early childhood development has fueled an interest in interventions aimed at mitigating these harmful consequences. Psychosocial interventions aimed at alleviating the negative impacts of poverty on children are frequently shown to be of benefit, but effect sizes are typically small to moderate. However, averaging outcomes over an entire sample, as is typically done, could underestimate efficacy because weaker effects on less susceptible individuals would dilute estimation of effects on those more disposed to respond. This study investigates whether a genetic polymorphism of the serotonin transporter gene moderates susceptibility to a psychosocial intervention.Methods and findingsWe reanalyzed data from a randomized controlled trial of a home-visiting program delivered by community health workers in a black, isiXhosa-speaking population in Khayelitsha, South Africa. The intervention, designed to enhance maternal-infant attachment, began in the third trimester and continued until 6 mo postpartum. Implemented between April 1999 and February 2003, the intervention comprised 16 home visits delivered to 220 mother–infant dyads by specially trained community health workers. A control group of 229 mother–infant dyads did not receive the intervention. Security of maternal-infant attachment was the main outcome measured at infant age 18 mo. Compared to controls, infants in the intervention group were significantly more likely to be securely attached to their primary caregiver (odds ratio [OR] = 1.7, p = 0.029, 95% CI [1.06, 2.76], d = 0.29). After the trial, 162 intervention and 172 control group children were reenrolled in a follow-up study at 13 y of age (December 2012–June 2014). At this time, DNA collected from 279 children (134 intervention and 145 control) was genotyped for a common serotonin transporter polymorphism. There were both genetic data and attachment security data for 220 children (110 intervention and 110 control), of whom 40% (44 intervention and 45 control) carried at least one short allele of the serotonin transporter gene. For these 220 individuals, carrying at least one short allele of the serotonin transporter gene was associated with a 26% higher rate of attachment security relative to controls (OR = 3.86, p = 0.008, 95% CI [1.42, 10.51], d = 0.75), whereas there was a negligible (1%) difference in security between intervention and control group individuals carrying only the long allele (OR = 0.95, p = 0.89, 95% CI [0.45, 2.01], d = 0.03). Expressed in terms of absolute risk, for those with the short allele, the probability of secure attachment being observed in the intervention group was 84% (95% CI [73%, 95%]), compared to 58% (95% CI [43%, 72%]) in the control group. For those with two copies of the long allele, 70% (95% CI [59%, 81%]) were secure in the intervention group, compared to 71% (95% CI [60%, 82%]) of infants in the control group. Controlling for sex, maternal genotype, and indices of socioeconomic adversity (housing, employment, education, electricity, water) did not change these results. A limitation of this study is that we were only able to reenroll 49% of the original sample randomized to the intervention and control conditions. Attribution of the primary outcome to causal effects of intervention in the present subsample should therefore be treated with caution.ConclusionsWhen infant genotype for serotonin transporter polymorphism was taken into account, the effect size of a maternal-infant attachment intervention targeting impoverished pregnant women increased more than 2.5-fold when only short allele carriers were considered (from d = 0.29 for all individuals irrespective of genotype to d = 0.75) and decreased 10-fold when only those carrying two copies of the long allele were considered (from d = 0.29 for all individuals to d = 0.03). Genetic differential susceptibility means that averaging across all participants is a misleading index of efficacy. The study raises questions about how policy-makers deal with the challenge of balancing equity (equal treatment for all) and efficacy (treating only those whose genes render them likely to benefit) when implementing psychosocial interventions.Trial RegistrationCurrent Controlled Trials ISRCTN25664149

Association between polymorphisms in the human serotonin transporter gene and lifelong premature ejaculation in the Han population

Association between polymorphisms in the human serotonin transporter gene and lifelong premature ejaculation in the Han population

Serotonin Transporter Gene (SLC6A4) Polymorphism and Mucosal Serotonin Levels in Southeastern Iranian Patients with Irritable Bowel Syndrome.

BACKGROUND Irritable bowel syndrome (IBS) is a digestive system disorder with an unknown etiology. Serotonin has a key role in the secretion and motility of the intestine. Polymorphism in serotonin re-uptake transporter (SERT or SLC6A4) gene may have a functional role in the gut of patients with IBS. The aims of the present study were to investigate the association between SLC6A4 gene polymorphism and IBS and to detect the correlation between rectal serotonin levels and IBS sub-types. METHODS SLC6A4 gene polymorphism in 131 patients with IBS and 211 healthy controls were analysed using the quantitative polymerase chain reaction high-resolution melting (qPCR-HRM) curve technique. Serotonin was measured in rectal biopsies of patients with IBS using the enzyme-linked immunosorbent assay (ELISA) method. RESULTS The patients were categorized into three groups: IBS with diarrhoea (IBS-D): 70 patients, IBS with constipation (IBS-C): 18 patients, and IBS with mixed symptoms (IBS-M): 43 patients. The frequency of SLC6A4 s/s and l/s genotypes was significantly higher in IBS-C than IBS-D, IBS-M, and controls (p=0.036). Serotonin levels were similar in IBS sub-types. CONCLUSION SLC6A4 polymorphism is a possible candidate gene associated with the pathogenesis of IBS-C. Although serotonin levels did not differ in rectal biopsies of IBS sub-types, further investigation is recommended.

The correlation between 5-serotonin transporter gene polymorphism and the first episode major depressive disorder and cognitive function in adolescents

Objective To study the correlation between 5- serotonin transporter (5-HTT) gene polymorphism and the first episode major depressive disorder(MDD) and cognitive function in adolescent. Methods 5-HTT genotype and allele were detected by polymerase chain reaction (PCR) amplification of 76 patients with first episode of MDD and 73 normal controls.Case control method was used to analyze the correlation between different genotypes and the onset, the clinical features, and cognitive function. Results There was no significant difference between 5-HTTLPR genotype frequencies for the 41 cases of type S/S(53.9%), 27 cases of type L/S(35.5%), 8 cases of type L/L(10.5%)of case group and 5-HTTLPR genotype frequencies for the 38 cases of type S/S(52.1%), 18 cases of type L/S(24.7%), 17 cases of type L/L(23.3%) of control group(P>0.05). Patients with S/S type, L/S type had significantly higher sleep scores than those of patients with type L/L(P=0.005, P=0.001). Agitation score in patients with S/S type group was significantly higher than that in patients with S/L, L/L(P=0.000, P=0.001); patients with S/S inferiority scores were significantly lower than those of patients with S/L, L/L(P=0.002, P=0.006). There was no significant difference in cognitive function among three groups. Conclusions In Chinese Han population, there may be no direct association between 5-HTTLPR gene polymorphism and susceptibility to MDD and its cognitive function in adolescents. S/S and L/S patients may be prone to sleep problems, type S/S patients may be prone to irritability and type L/L patients may be prone to inferiority. Key words: Adolescents; Major depressive disorder; Serotonin transporter; Gene polymorphism; Cognitive function

Interactive effects of 5-HTTLPR genotype and rearing environment on affective attitude towards own infant in Japanese mothers

Maternal positive attitude towards one’s own infant is the cornerstone of effective parenting. Previous research has revealed an influence of both genetic and environmental factors on maternal parenting behavior, but little is known of the potential gene-environment interaction in shaping a mother’s affective attitude. To address this gap, we investigated the effect of a mother’s childhood rearing environment and a serotonin transporter gene polymorphism (5-HTTLPR) on affective attitude towards her infant.Our analyses found an interactive effect between rearing environment and 5-HTTLPR genotype on maternal attitude. Specifically, a poor rearing environment (characterized by low maternal care and high paternal overprotection) decreased positive attitude towards one’s own infant in mothers with homozygous short allele genotype. In contrast, this detrimental effect was almost eliminated in long allele carriers. Altogether, our results indicate that the 5-HTTLPR gene moderates the influence of experienced rearing environment on maternal parental behavior in a manner consistent with the notion that the short 5-HTTLPR allele amplifies environmental influence.