Maternal childhood adversity and child temperament: An association moderated by child 5‐HTTLPR genotype

We examined transgenerational effects of maternal childhood adversity on child temperament and a functional promoter polymorphism, 5‐HTTLPR, in the serotonin‐transporter gene (SLC6A4) as potential moderators of such maternal influences in 154 mother–child dyads, recruited into a longitudinal birth cohort study. We examined the interactive effects of maternal childhood experience using an integrated measure derived from Childhood Trauma Questionnaire (CTQ) and Parental Bonding Index (PBI). Triallelic genotyping of 5‐HTTLPR was performed. A measure of ‘negative emotionality/behavioural dysregulation’ was derived from the Early Childhood Behaviour Questionnaire at 18 and 36 months. Negative emotionality/behavioural dysregulation was highly stable between 18 and 36 months and predicted psychosocial problems at 60 months. After controlling multiple demographics as well as both previous and concurrent maternal depression there was a significant interaction effect of maternal childhood adversity and offspring 5‐HTTLPR genotype on child negative emotionality/behavioural dysregulation (β = 1.03, t_11,115 = 2.71, P < .01). The results suggest a transgenerational effect of maternal developmental history on emotional function in the offspring, describing a pathway that likely contributes to the familial transmission of vulnerability for psychopathology.     

5‐HTTLPR genotype potentiates the effects of war zone stressors on the emergence of PTSD,depressive and anxiety symptoms in soldiers deployed to iraq

Exposure to war zone stressors is common, yet only a minority of soldiers experience clinically meaningful disturbance in psychological function. Identification of biomarkers that predict vulnerability to war zone stressors is critical for developing more effective treatment and prevention strategies not only in soldiers but also in civilians who are exposed to trauma. We investigated the role of the serotonin transporter linked polymorphic region (5‐HTTLPR) genotype in predicting the emergence of post‐traumatic stress disorder (PTSD), depressive and anxiety symptoms as a function of war zone stressors. A prospective cohort of 133 U.S. Army soldiers with no prior history of deployment to a war zone, who were scheduled to deploy to Iraq, was recruited. Multilevel regression models were used to investigate associations between 5‐HTTLPR genotype, level of war zone stressors, and reported symptoms of PTSD, depression and anxiety while deployed to Iraq. Level of war zone stressors was associated with symptoms of PTSD, depression and anxiety. Consistent with its effects on stress responsiveness, 5‐HTTLPR genotype moderated the relationship between level of war zone stressors and symptoms of emotional disturbance. Specifically, soldiers carrying one or two low functioning alleles (S or L_G) reported heightened symptoms of PTSD, depression and anxiety in response to increased levels of exposure to war zone stressors, relative to soldiers homozygous for the high functioning allele (L_A). These data suggest that 5‐HTTLPR genotype moderates individual sensitivity to war zone stressors and the expression of emotional disturbance including PTSD symptoms. Replication of this association along with identification of other genetic moderators of risk can inform the development of biomarkers that can predict relative resilience vs. vulnerability to stress.     

Predictors for self‐directed aggression in Italian prisoners include externalizing behaviors,childhood trauma and the serotonin transporter gene polymorphism 5‐HTTLPR

Suicidal behavior and self‐mutilation can be regarded as the expression of self‐directed aggression and both are common in prison populations. We investigated the influence of externalizing behaviors, depressive symptoms, childhood trauma, 5‐HTTLPR variants on self‐directed aggression (N = 145) in a group of 702 male Italian prisoners. Participants were comprehensively evaluated, including for psychiatric disorders, impulsive traits, lifetime aggressive behavior [Brown‐Goodwin Lifetime History of Aggression (BGHA)], hostility, violent behavior during incarceration, depressive symptomatology [Hamilton Depression Rating Scale (HDRS)], childhood trauma [Childhood Trauma Questionnaire (CTQ)]. Logistic regression analysis showed false discovery rate corrected independent main effects of externalizing behaviors: BGHA (P = 0.001), violent behavior in jail (P = 0.007), extraversion (P = 0.015); HDRS (P = 0.0004), Axis I disorders (P = 0.015), CTQ (P = 0.004) and 5‐HTTLPR genotype (P = 0.02). Carriers of 5‐HTTLPR high (L_AL_A), intermediate (L_AL_G, SL_A) activity variants were more likely to have exhibited self‐directed aggression relative to the low activity (L_GL_G, SL_G, SS) variant: high/low: odds ratio (OR) = 2.3, 95% confidence interval (CI) 1.27–4.68, P = 0.007; intermediate/low: OR = 1.96, 95% CI 1.09–3.68, P = 0.025. The CTQ main effect was driven by physical abuse. There was no interactive effect of 5‐HTTLPR and CTQ. Secondary logistic regression analyses in (1) all suicide attempters (N = 88) and (2) all self‐mutilators (N = 104), compared with controls showed that in both groups, childhood trauma (P = 0.008–0.01), depression (P = 0.0004–0.001) were strong predictors. BGHA, violent behavior in jail predicted self‐mutilation (P = 0.002) but not suicide attempts (P = 0.1). This study was able to distinguish differing influences on self‐directed aggression between groups of closely related predictor variables within the externalizing behavioral domain. 5‐HTTLPR had an independent, variant dosage effect.     

Prefrontal morphology, 5‐HTTLPR polymorphism and biased attention for emotional stimuli

Biased attention for emotional stimuli has been associated with vulnerability to psychopathology. This study examines the neural substrates of biased attention. Twenty‐three adult women completed high‐resolution structural imaging followed by a standard behavioral measure of biased attention (i.e. spatial cueing task). Participants were also genotyped for the serotonin transporter‐linked promoter region (5‐HTTLPR) gene. Results indicated that lateral prefrontal cortex (lPFC) morphology was inversely associated with maintained attention for positive and negative stimuli, but only among short 5‐HTTLPR allele carriers. No such associations were observed for the medial prefrontal cortex (mPFC) or the amygdala. Results from this study suggest that brain regions involved in cognitive control of emotion are also associated with attentional biases for emotion stimuli among short 5‐HTTLPR allele carriers.     

Allele polymorphism of the serotonin transporter gene and clinical heterogeneity of depressive disorders

Depression disorders are a clinically heterogeneous disease group. Their development is to a substantial extent underlain by dysfunction of the serotonin system, in particular, disturbed serotonin transport. The heterogeneity of depressions is associated, among other factors, with the age at disease onset. Allele polymorphism of the serotonin transporter (5-HTT) gene was tested for association with age at disease onset, clinical signs, and anxiety-related traits of depression patients. A sample included 77 patients (mean age 61.2 +/- 8.8 years) with late-onset depression (LOD, mean age at onset 56.58 +/- 9.7 years) and 74 patients (mean age 31.0 +/- 11.8 years) with early-onset depression (EOD, mean age at onset 23.9 +/- 7.4 years). In genotype frequency distribution of two 5-HTT gene polymorphism, the LOD and EOD groups did not differ from each other (chi 2 = 0.33, P = 0.85 for VNTR-17; chi 2 = 3.33, P = 0.19 for HTTLPR) and from a control group (chi 2 = 0.34, P = 0.84 for VNTR-17; chi 2 = 2.1, P = 0.35 for HTTLPR). In either group, patients differing in VNTR-17 and HTTLPR genotypes did not differ in psychological traits and, in particular, in anxiety-related traits. In the case of the HTTLPR polymorphism, LOD patients with genotype ss tended to display less severe neuroticism (t = 2.03, P = 0.0507) and scored significantly less on the Hamilton depression scale (t = 2.19, P = 0.039). Thus, the 5-HTT gene polymorphisms do not affect the risk of depression but is possibly associated with specific clinical signs of the disease, at least in elderly patients.     

Childhood Maltreatment in Extremely Obese Male and Female Bariatric Surgery Candidates**

Objective: To examine rates of self‐reported childhood maltreatment in extremely obese bariatric surgery candidates and to explore associations with sex, eating disorder features, and psychological functioning. Research Methods and Procedures: Three hundred forty (58 men and 282 women) extremely obese consecutive candidates for gastric bypass surgery completed a questionnaire battery. The Childhood Trauma Questionnaire was given to assess childhood maltreatment. Results: Overall, 69% of patients self‐reported childhood maltreatment: 46% reported emotional abuse, 29% reported physical abuse, 32% reported sexual abuse, 49% reported emotional neglect, and 32% reported physical neglect. Except for higher rates of emotional abuse reported by women, different forms of maltreatment did not differ significantly by sex. Different forms of maltreatment were generally not associated with binge eating, current BMI, or eating disorder features. At the Bonferonni‐corrected significance level, emotional abuse was associated with higher eating concerns and body dissatisfaction, and emotional neglect was associated with higher eating concerns. In terms of psychological functioning, at the Bonferonni‐corrected level, emotional abuse and emotional neglect were associated with higher depression and lower self‐esteem, and physical abuse was associated with higher depression. Discussion: Extremely obese bariatric surgery candidates reported rates of maltreatment comparable with those reported by clinical groups and roughly two to three times higher than normative community samples. Reported experiences of maltreatment differed little by sex and were generally not significantly associated with current BMI, binge eating, or eating disorder features. In contrast, maltreatment—notably emotional abuse and neglect—were significantly associated with higher depression and lower self‐esteem.     

Evidence for plasticity genotypes in a gene–gene–environment interaction: the TRAILS study

The purpose was to study how functional polymorphisms in the brain derived neurotrophic factor gene (BDNF val66met) and the serotonin transporter gene linked promotor region (5‐HTTLPR) interact with childhood adversities in predicting Effortful Control. Effortful Control refers to the ability to regulate behavior in a goal‐directed manner and is an interesting endophenotype for psychopathology because of its heritability and the association of low Effortful Control with both internalizing and externalizing problems. In a longitudinal population‐based study Effortful Control was assessed with the parent version of the Early Adolescent Temperament Questionnaire at age 11. Pregnancy and delivery adversities and childhood events were assessed in a parent interview at age 11. Long‐term difficulties until age 11 were assessed with a parent questionnaire at age 13.5. Blood or buccal cells were collected at age 16 for genotyping the rs6265 and rs25531 SNPs and the 5‐HTTLPR length polymorphism. The study included 1032 complete data sets. Effortful Control was significantly predicted by the interaction between BDNF val66met, 5‐HTTLPR and childhood events. The BDNF val66met val/val–5‐HTTLPR l′/l′ genotype was unaffected by childhood events, while having either at least one BDNF val66met met or 5‐HTTLPR s′ allele (l′/l′‐met‐carrier; l′/s′‐val/val; s′/s′‐val/val) made children sensitive to childhood events. Predictions of Effortful Control by pregnancy and delivery adversities and long‐term difficulties were largely independent of genotype. We concluded that the l′/l′‐met‐carrier, l′/s′‐val/val and the s′/s′‐val/val genotypes showed greatest plasticity while the l′/l′‐val/val genotype was unaffected by childhood events.     

COMT but not serotonin‐related genes modulates the influence of childhood abuse on anger traits

Anger‐related traits are regulated by genes as well as early environmental factors. Both childhood maltreatment and genes underlie vulnerability to suicidal behaviors, possibly by affecting the constitution of intermediate phenotypes such as anger traits. The aim of this study was to test the interaction between nine candidate genes and childhood maltreatment in modulating anger‐related traits in 875 adult suicide attempters. The State‐Trait Anger Expression Inventory and the Childhood Trauma Questionnaire were used to examine anger traits and traumatic childhood experiences, respectively. The functional polymorphism of the catecholamine‐O‐methyl‐transferase (COMT) gene Val158Met significantly modulated the association between sexual abuse and anger‐trait level (P = 0.001). In the presence of sexual abuse, individuals carrying the Val high‐activity allele displayed greater disposition toward anger than individuals homozygous for the Met allele (P = 0.0003). Notably, none of the serotonin‐related genes influenced the effect of childhood abuse on anger traits. The results of the present study suggest that anger‐trait level is influenced by the interaction between childhood abuse and functional polymorphism in the COMT gene. This study was carried out in a population with a high frequency of childhood abuse and a high disposition toward anger, and replication in healthy subjects is needed.     

Face and emotion expression processing and the serotonin transporter polymorphism 5‐HTTLPR/rs22531

Face cognition, including face identity and facial expression processing, is a crucial component of socio‐emotional abilities, characterizing humans as highest developed social beings. However, for these trait domains molecular genetic studies investigating gene–behavior associations based on well‐founded phenotype definitions are still rare. We examined the relationship between 5‐HTTLPR/rs25531 polymorphisms – related to serotonin‐reuptake – and the ability to perceive and recognize faces and emotional expressions in human faces. For this aim we conducted structural equation modeling on data from 230 young adults, obtained by using a comprehensive, multivariate task battery with maximal effort tasks. By additionally modeling fluid intelligence and immediate and delayed memory factors, we aimed to address the discriminant relationships of the 5‐HTTLPR/rs25531 polymorphisms with socio‐emotional abilities. We found a robust association between the 5‐HTTLPR/rs25531 polymorphism and facial emotion perception. Carriers of two long (L) alleles outperformed carriers of one or two S alleles. Weaker associations were present for face identity perception and memory for emotional facial expressions. There was no association between the 5‐HTTLPR/rs25531 polymorphism and non‐social abilities, demonstrating discriminant validity of the relationships. We discuss the implications and possible neural mechanisms underlying these novel findings.     

Influence of the 5-HT3A Receptor Gene Polymorphism and Childhood Sexual Trauma on Central Serotonin Activity

Background

Gene-environment interactions are important for understanding alterations in human brain function. The loudness dependence of auditory evoked potential (LDAEP) is known to reflect central serotonergic activity. Single nucleotide polymorphisms (SNPs) in the 5-HT3A serotonin receptor gene are associated with psychiatric disorders. This study aimed to investigate the effect between 5-HT3A receptor gene polymorphisms and childhood sexual trauma on the LDAEP as an electrophysiological marker in healthy subjects.

Methods

A total of 206 healthy subjects were recruited and evaluated using the childhood trauma questionnaire (CTQ) and hospital anxiety and depression scale (HADS). Peak-to-peak N1/P2 was measured at five stimulus intensities, and the LDAEP was calculated as the linear-regression slope. In addition, the rs1062613 SNPs of 5-HT3A (CC, CT, and TT) were analyzed in healthy subjects.

Results

There was a significant interaction between scores on the CTQ-sexual abuse subscale and 5-HT3A genotype on the LDAEP. Subjects with the CC polymorphism had a significantly higher LDEAP than T carriers in the sexually abused group. In addition, CC genotype subjects in the sexually abused group showed a significantly higher LDAEP compared with CC genotype subjects in the non-sexually abused group.

Conclusions

Our findings suggest that people with the CC polymorphism of the 5-HT3A gene have a greater risk of developing mental health problems if they have experienced childhood sexual abuse, possibly due to low central serotonin activity. Conversely, the T polymorphism may be protective against any central serotonergic changes following childhood sexual trauma.     

Childhood Psychological,Physical, and Sexual Maltreatment in Outpatients with Binge Eating Disorder: Frequency and Associations with Gender,Obesity, and Eating‐Related Psychopathology

Objective: To examine rates of reported childhood maltreatment in binge eating disorder (BED), and to explore associations with obesity, gender, eating disorder features, and associated functioning. Research Methods and Procedures: Subjects were 145 consecutive outpatients with BED as defined in the Diagnostic and Statistical Manual of Mental Disorders, 4^th edition. Subjects were interviewed and they completed questionnaires to assess eating disorder features and functioning. The Childhood Trauma Questionnaire was given to assess childhood maltreatment in five domains (emotional abuse, physical abuse, sexual abuse, emotional neglect, and physical neglect). Results: A total of 83% of BED patients reported some form of childhood maltreatment. A total of 59% of BED patients reported emotional abuse, 36% reported physical abuse, 30% reported sexual abuse, 69% reported emotional neglect, and 49% reported physical neglect. There were no differences in the distribution of any form of childhood maltreatment by gender or by obesity status. The different forms of maltreatment were not associated with variability in current body mass index, binge eating, or in the attitudinal features of eating disorders. Only one of the five forms of maltreatment (physical neglect) was associated with dietary restraint in women. Emotional abuse was significantly associated with greater body dissatisfaction, higher depression, and lower self‐esteem in men and women and sexual abuse was associated with greater body dissatisfaction in men. The different forms of maltreatment were unrelated to the age at onset of overweight, dieting, or binge eating. Discussion: BED outpatients reported a wide range of childhood experiences of maltreatment that do not differ by gender or obesity status. Different forms of maltreatment were not associated with the onset of overweight, dieting, or binge eating, or with variability in current body mass index or eating disorder features (except for one association between physical neglect and dietary restraint). Reports of emotional abuse were associated with greater body dissatisfaction and depression and lower self‐esteem in men and women and sexual abuse with greater body dissatisfaction in men.     

CREB1 modulates the influence of childhood sexual abuse on adult's anger traits

Childhood maltreatment and genes underlie vulnerability to suicidal behaviours (SB), possibly by affecting the constitution of endophenotypes such as anger traits. The CREB protein has been implicated in antidepressant response, suicide and mood disorders in general. The aim of this study was to investigate if CREB1 gene is associated with SB and/or anger-related traits and if these associations are modulated by childhood maltreatment. Five hundred and thirty-four male suicide attempters and 357 male non-suicide attempters were genotyped for several polymorphisms within CREB1 gene. Four hundred and thirty-seven (156 non-suicide attempters and 281 suicide attempters) completed the State-Trait Anger Expression Inventory (STAXI) and 288 (265 suicide attempters and 23 controls) fulfilled the Childhood Trauma Questionnaire (CTQ). In total, 72 males had experienced childhood sexual abuse. Our results did not show any significant association between CREB1 and suicide behaviour. We found a significant interaction showing that CREB1 rs4675690 polymorphism modulated the effect of childhood sexual abuse on adulthood anger-out levels (P = 0.003). Sexually abused subjects carrying the CC genotype showed higher anger-out scores than T allele carriers, whereas no difference was observed in non-sexually abused subjects. CREB1 rs4675690 polymorphism modulates the association between childhood sexual abuse and adulthood anger-trait level. This is, to our knowledge, the first study to show such an interaction and to highlight the main effect of this gene on modulating the effect of child abuse on psychopathologies and warrant further investigation on this topic.     

Allele Polymorphism of the Serotonin Transporter Gene and Clinical Heterogeneity of Depressions

Depression disorders are a clinically heterogeneous disease group. Their development is to a substantial extent underlain by dysfunction of the serotonin system, in particular, disturbed serotonin transport. The heterogeneity of depressions is associated, among other factors, with the age at disease onset. Allele polymorphism of the serotonin transporter (5-HTT) gene was tested for association with age at disease onset, clinical signs, and anxiety-related traits of depression patients. A sample included 77 patients (mean age 61.2 ± 8.8 years) with late-onset depression (LOD, mean age at onset 56.58 ± 9.7 years) and 74 patients (mean age 31.0 ± 11.8 years) with early-onset depression (EOD, mean age at onset 23.9 ± 7.4 years). In genotype frequency distribution of two 5-HTT gene polymorphisms, the LOD and EOD groups did not differ from each other (² = 0.33, P = 0.85 for VNTR; ² = 3.33, P = 0.19 for HTTLPR) and from a control group (² = 0.34,P = 0.84 for VNTR; ² = 2.1, P= 0.35 for HTTLPR). In either group, patients differing in VNTR and HTTLPR genotypes did not differ in psychological traits and, in particular, in anxiety-related traits. In the case of the HTTLPR polymorphism, LOD patients with genotype sstended to display less severe neuroticism (t= 2.03, P = 0.0507) and scored significantly less on the Hamilton depression scale (t = 2.19, P = 0.039). Thus, the 5-HTT gene polymorphisms do not affect the risk of depression but is possibly associated with specific clinical signs of the disease, at least in elderly patients.     

Lack of Association Between Down Syndrome and Polymorphisms in Dopamine Receptor D4 and Serotonin Transporter Genes

Down Syndrome (DS) patients suffer from cognitive dysfunction, depression, hyperactivity, irritability etc. Dopamine (DA) and serotonin (5HT) are known to control cognitive and behavioral attributes. An increased number of the DA receptor 4 (DRD4) is detected in brain regions primarily involved in cognition. Impairments in executive function have also been reported with depletion in 5HT. A variable number of tandem repeat (VNTR) in the exon 3 of DRD4 and an insertion/deletion polymorphism in the promoter region of 5HT transporter (5HTTLPR) have been found to be associated with different neurobehavioral disorders; however, association of these polymorphisms with DS has never been explored. The present family-based analysis on DS revealed significant over-transmission of a DRD4 VNTR allele which encodes for D4 receptor with average activity. No association was noticed for the 5HTTLPR. We may conclude that these genetic polymorphisms are not contributing to the neuromotor and cognitive dysfunctions observed in DS.     

Looking on the bright side: biased attention and the human serotonin transporter gene

Humans differ in terms of biased attention for emotional stimuli and these biases can confer differential resilience and vulnerability to emotional disorders. Selective processing of positive emotional information, for example, is associated with enhanced sociability and well-being while a bias for negative material is associated with neuroticism and anxiety. A tendency to selectively avoid negative material might also be associated with mental health and well-being. The neurobiological mechanisms underlying these cognitive phenotypes are currently unknown. Here we show for the first time that allelic variation in the promotor region of the serotonin transporter gene (5-HTTLPR) is associated with differential biases for positive and negative affective pictures. Individuals homozygous for the long allele (LL) showed a marked bias to selectively process positive affective material alongside selective avoidance of negative affective material. This potentially protective pattern was absent among individuals carrying the short allele (S or SL). Thus, allelic variation on a common genetic polymorphism was associated with the tendency to selectively process positive or negative information. The current study is important in demonstrating a genotype-related alteration in a well-established processing bias, which is a known risk factor in determining both resilience and vulnerability to emotional disorders.     

White matter microstructure in bipolar disorder is influenced by the serotonin transporter gene polymorphism 5‐HTTLPR

Bipolar disorder (BD) is associated with signs of widespread disruption of white matter (WM) integrity. A polymorphism in the promoter of the serotonin transporter (5‐HTTLPR) influenced functional cortico‐limbic connectivity in healthy subjects and course of illness in BD, with the short (s) allele being associated with lower functional connectivity, and with earlier onset of illness and poor response to treatment. We tested the effects of 5‐HTTLPR on diffusion tensor imaging (DTI) measures of WM microstructure in 140 inpatients, affected by a major depressive episode in course of BD, of Italian descent. We used whole brain tract‐based spatial statistics in the WM skeleton with threshold‐free cluster enhancement of DTI measures of WM microstructure: axial, radial and mean diffusivity and fractional anisotropy. Compared with l/l homozygotes, 5‐HTTLPR*s carriers showed significantly increased radial and mean diffusivity in several brain WM tracts, including corpus callosum, cingulum bundle, uncinate fasciculus, corona radiata, thalamic radiation, inferior and superior longitudinal fasciculus and inferior fronto‐occipital fasciculus. An increase of mean and radial diffusivity, perpendicular to the main axis of the WM tract, is thought to signify increased space between fibers, thus suggesting demyelination or dysmyelination, or loss of bundle coherence. The effects of 5‐HTTLPR on the anomalous emotional processing in BD might be mediated by changes of WM microstructure in key WM tracts contributing to the functional integrity of the brain.     

Associations between chronotypes and psychological vulnerability factors of depression

Chronotypes have been associated with psychopathology. The eveningness chronotype has been consistently linked with depressed states or depressive disorder, but the underlying mechanism remains unclear. Prior studies have shown associations between chronotype and personality traits that are linked to depression (e.g. neuroticism), but other psychological vulnerability factors have not been previously investigated in relation to chronotypes. The aim of this study was to examine the association between chronotypes, depression and psychological risk factors of depression (namely, cognitive reactivity and worry), in a large cohort of depressed patients and healthy individuals. We used data from the Netherlands Study of Depression and Anxiety (n = 1654), which includes 1227 clinically diagnosed individuals with a lifetime diagnosis of depression and 427 healthy controls. We assessed cognitive reactivity (Leiden Index of Depression Sensitivity-Revised) and trait worry (Penn State Worry Questionnaire). We controlled for sociodemographic factors as well as for insomnia and neuroticism. We found that the evening type is associated with higher cognitive reactivity scores, especially with increased rumination. Cognitive reactivity also mediated the relationship between chronotype and depression status, even when controlling for neuroticism and insomnia. Trait worry was not associated with chronotype. Our findings show that depressogenic cognitions are more prevalent in evening types and perhaps mediate the association between chronotype and depression. Further prospective research is needed to determine the timeline of the association. Nevertheless, results imply that targeting depressogenic cognitive processes, perhaps in combination with chronotherapeutic treatments, may be particularly useful in evening types.     

No Evidence for the Association between a Polymorphism in the PCLO Depression Candidate Gene with Memory Bias in Remitted Depressed Patients and Healthy Individuals

The PCLO rs2522833 candidate polymorphism for depression has been associated to monoaminergic neurotransmission. In healthy and currently depressed individuals, the polymorphism has been found to affect activation of brain areas during memory processing, but no direct association of PCLO with memory bias was found. We hypothesized that the absence of this association might have been obscured by current depressive symptoms or genetically driven individual differences in reactivity to stressful events. Experiencing stressful childhood events fosters dysfunctional assumptions that are related to cognitive biases, and may modulate the predisposition for depression via epigenetic effects. The association between PCLO and memory bias, as well as interaction between PCLO and childhood events was studied in patients remitted from depression (N = 299), as well as a sample of healthy individuals (N = 157). The participants performed an emotional verbal memory task after a sad mood induction. Childhood trauma and adversity were measured with a questionnaire. The Genotype main effect, and Genotype by Childhood Events interaction were analyzed for memory bias in both samples. PCLO risk allele carrying remitted depressed patients did not show more negatively biased memory than non-risk allele carriers, not even patients with stressful childhood events. A similar pattern of results was found in healthy individuals. Memory bias may not be strongly associated with the PCLO rs2522833 polymorphism. We did not find any support for the PCLO-childhood events interaction, but the power of our study was insufficient to exclude this possibility.     

Contribution of the functional 5-HTTLPR variant of the SLC6A4 gene to obesity risk in male adults

Background: A polymorphism in the promoter region of the serotonin transporter (5‐HTTLPR) gene SLC6A4 shows functionally important 44‐bp insertion/deletion alleles: long (L) and short (S). We have previously found that the S allele is a genetic risk factor for obesity in adolescents. Objective: The aim of this study was to evaluate whether the S/L variant of the SLC6A4 gene is associated with BMI as a continuous trait and also with obesity in a large sample of adult men of European ancestry included in a cross‐sectional, population‐based study. Methods and Procedures: The study group was composed of individuals who were randomly recruited from a factory in the Buenos Aires metropolitan area and who underwent an annual health examination. Results: We observed that among 1,329 unrelated subjects, aged 34.6 ± 0.3 years, age‐adjusted BMI values (expressed as mean ± s.e.) for each genotype showed statistically significant differences across genotypic groups (LL: 25.4 ± 0.2, LS: 26.0 ± 0.1 and SS: 26.7 ± 0.2, P < 0.0002). In addition, association tests showed that the 5‐HTTLPR‐genotype distribution was significantly different between 692 lean (BMI ≤ 25 kg/m2) and 637 obese (BMI ≥ 27 kg/m2) individuals. We found a 1.36 odds ratio (OR) (95% CI 1.01–1.85) for obesity in SS carriers in comparison with LL carriers, P = 0.026. Discussion: In conclusion, our findings indicate that 5‐HTTLPR polymorphism may be linked with BMI and also with obesity and/or overweight in adult male population, reinforcing the role of the serotonin transporter as a risk factor for the obesity phenotype and suggesting potential new avenues for its pharmacological treatment.     

Affected by smells? Environmental chemical responsivity predicts odor perception

Strong negative reactions, physical symptoms, and behavioral disruptions due to environmental odors are common in the adult population. We investigated relationships among such environmental chemosensory responsivity (CR), personality traits, affective states, and odor perception. Study 1 showed that CR and neuroticism were positively correlated in a sample of young adults (n = 101), suggesting that persons high in neuroticism respond more negatively to environmental odors. Study 2 explored the relationships among CR, noise responsivity (NR), neuroticism, and odor perception (i.e., pleasantness and intensity) in a subset of participants (n = 40). High CR was associated with high NR. Regression analyses indicated that high CR predicted higher odor intensity ratings and low olfactory threshold (high sensitivity) predicted lower pleasantness ratings. However, neuroticism was not directly associated with odor ratings or thresholds. Overall, the results suggest that CR and odor thresholds predict perceptual ratings of odors and that high CR is associated with nonchemosensory affective traits.