Tamlin S. Conner

Interactive Effects of the Serotonin Transporter 5-HTTLPR Polymorphism and Stressful Life Events on College Student Drinking and Drug Use

BACKGROUND A common functional polymorphism, 5-HTTLPR, in the serotonin transporter gene has been associated with heavy drinking in college students. We examined this polymorphism as it interacted with negative life events to predict drinking and drug use in college students. METHODS Daily reports of drinking and drug use obtained using a daily web-based survey were combined with self-reports of past-year negative life events and 5-HTTLPR genotypes in a regression analysis of alcohol and nonprescribed drug use in a sample of 295 college students. RESULTS Genotype and negative life events significantly interacted in relation to drinking and drug use outcomes. Individuals homozygous for the short (s) allele who experienced multiple negative life events in the prior year reported more frequent drinking and heavy drinking, stronger intentions to drink, and greater nonprescribed drug use. In individuals homozygous for the long (l) allele, drinking and drug use were unaffected by past-year negative life events. Heterozygous subjects showed drinking outcomes that were intermediate to the two homozygous groups. CONCLUSIONS The 5-HTTLPR s-allele is associated with increased drinking and drug use among college students who have experienced multiple negative life events. The s-allele carriers may be at risk for a variety of adverse behavioral outcomes in response to stress.

A common polymorphism in serotonin receptor 1B mRNA moderates regulation by miR-96 and associates with aggressive human behaviors

Non-coding regulatory elements can transduce the human genomes response to environmental stimuli. Thus, there is a possibility that variation in non-coding regulatory elements may underlie some of the diversity in human behavior. However, this idea has remained largely untested due to the difficulty in accurately identifying regulatory elements in the 98% of the human genome that does not encode protein. The recent recognition that small trans-acting RNAs anneal to mRNA and regulate gene expression provides a means to identify and test such variants. Here, we show that microRNA-directed silencing of mRNA can be attenuated by a common human polymorphism. We have identified an element (A-element) within serotonin receptor 1B (HTR1B) mRNA that confers repression by miR-96. The repressive activity of this element is attenuated by a common human variant (G-element) that disrupts a nucleotide critical for its interaction with miR-96. Because deletion of the HTR1B gene leads to an aggressive phenotype in mice, we hypothesized an association between the A/G polymorphism and aggressive phenotypes in a sample of 359 college students. As predicted, individuals homozygous for the ancestral A-element reported more conduct-disorder behaviors than individuals with the G-element. Our studies suggest that such functional variants may be common and may help to refine the search for genes involved in complex behavioral disorders.

Serotonin transporter gene polymorphism (5-HTTLPR) and anxiety reactivity in daily life: a daily process approach to gene-environment interaction.

Objective: To test whether individuals with at least one copy of the short (S) or long (L)G allele of the serotonin transporter polymorphism (5-HTTLPR) exhibit greater increases in anxiety, compared with LALA individuals, under periods of high daily stress. Although this common polymorphism in the serotonin transporter gene has been identified as a vulnerability factor for anxiety, findings in the literature are mixed. Discrepant findings could be explained by recent research showing that 5-HTTLPR is functionally triallelic (LA versus LG or S), rather than biallelic (L versus S). Mixed findings could also result from a lack of attention to diathesis-stress models, whereby genetic vulnerability is considered latent until activated by stress (gene-environment interplay). Based on this model, we argue that genotype differences in anxiety should be stronger in the presence of stress. Methods: A total of 350 college students recorded their daily stressors and mood for two 30-day periods, separated by 1 year. Results: Across both years, diathesis-stress patterns were observed for reports of anxious mood as a function of 5-HTTLPR. Individuals with at least one copy of the S or LG allele at 5-HTTLPR experienced elevated anxious mood on days with more intense stressors, as compared with those who were LA homozygotes. Genotype differences in anxiety were less apparent on low stress days. No consistent allelic association of 5-HTTLPR was observed with any other mood states, trait anxiety, or neuroticism. Conclusion: Our findings highlight the potential value of focusing on genetic vulnerability in the context of everyday environmental triggers. 5-HTTLPR = serotonin transporter gene promoter polymorphism; 5-HTT = serotonin transporter protein; fMRI = functional magnetic resonance imaging; STAI = State-Trait Anxiety Inventory.

A Longitudinal Analysis of Drinking Motives Moderating the Negative Affect-Drinking Association Among College Students

We examined among college students (N = 530; 276 women) the moderating effects of avoidance (coping) and appetitive (social-enhancement) drinking motives on the within-person associations between anxious and depressive affect and drinking frequency and quantity. Once per year for up to 4 years participants completed standard measures of drinking motives and retrospective reports of affect and drinking in the previous month. In addition, each year they completed a 30-day daily diary of affect and drinking. Results from models examining both the retrospective and aggregate daily data indicated that individuals with high compared with low social-enhancement motives showed stronger positive associations among changes in monthly negative affect and drinking frequency. Weak evidence was found for the predicted moderating effects of coping motives, although some results indicated that its effects were contingent on levels of social-enhancement motives. Our findings suggest that appetitive drinking motives might play an integral role in stress- and negative-affect related drinking among college students.

Implicit Self-Attitudes Predict Spontaneous Affect in Daily Life

In 2 studies, the authors examined the degree to which implicit self-attitudes predicted peoples spontaneous affective experiences in daily life. Across both studies, implicit attitudes toward the self (as measured by Implicit Association Tests) strongly predicted negative feeling states (as measured by computerized experience-sampling procedures), suggesting that implicit self-attitudes may be linked to changes in undifferentiated negative affect. Explicit attitudes toward the self generally did not account for these relations. Findings extend understanding of the factors that contribute to experienced affect and are the first to empirically link implicit self-attitudes with phenomenological affective experience in real-life settings over time.

Coping with rheumatoid arthritis pain in daily life: Within-person analyses reveal hidden vulnerability for the formerly depressed

&NA; This study examined the association between history of depression and day‐to‐day coping with rheumatoid arthritis (RA) pain. The sample was 188 RA‐diagnosed participants, 73 of whom were identified by a structured clinical interview as having a history of major depression. None had current major depression. All participated in a 30‐day prospective study in which they made end‐of‐day ratings of their arthritis pain, the strategies for how they coped with their pain, their appraisals of daily pain, and daily mood. Hierarchical linear models evaluated whether individuals with and without depression history differed in their average pain and the other daily measures; and separately, whether they differed in their within‐person associations between pain and the daily measures (e.g., the day‐to‐day contingency between pain and mood). All analyses controlled for current mild depressive symptoms, neuroticism, and age. Previously depressed individuals were indistinguishable from their never depressed peers in their average pain and the other daily measures; however, the previously depressed exhibited significantly stronger associations between pain and several aspects of their daily emotional experience, suggesting more pain‐contingent well‐being. For individuals with a history of depression, increases in daily pain corresponded with more frequent efforts to cope with their pain by venting their emotions, significantly stronger impairments in mood, and, if they were also presently distressed, reduced perceptions of control over their pain, compared to the never depressed. Patterns suggest that formerly depressed individuals exhibit a hidden vulnerability in how they manage chronic pain. This vulnerability is best revealed by a daily process approach.

Functional polymorphisms in the serotonin 1B receptor gene (HTR1B) predict self‐reported anger and hostility among young men

We examined associations between haplotypes of the serotonin 1B receptor gene and individual differences in anger and hostility. Data were analyzed from a study of 361 university students (47% male). Participants were genotyped at five polymorphisms in the HTR1B gene (rs11568817, rs130058, rs6296, rs6297, rs13212041), including promoter and 3′UTR polymorphisms with opposite functional effects on gene expression. Participants reported their emotional states across 30 consecutive days for up to 4 years. Haplotype pairs were constructed statistically and assigned to a level of HTR1B expression based on the presence of the functional polymorphisms. Six haplotypes accounted for >97% of chromosomes. Three low expression haplotypes contained the 3′UTR variant (rs13212041 A‐allele) that enables a microRNA‐mediated reduction in expression. One intermediate expression haplotype contained the 3′UTR A‐allele paired with the high‐activity promoter. Two high expression haplotypes contained the 3′UTR variant (rs13212041 G‐allele) that attenuates microRNA‐mediated reduction in expression. Men with low expression haplotypes reported greater anger and hostility than men with one or two high expression haplotypes. Diplotype classification accounted for 8.4% of the variance in mens anger and hostility, primarily due to the 3′UTR polymorphism (rs13212041), but with some contribution of the functional promoter combination (rs11568817, rs130058). Associations with anger and hostility were not found in women. These findings extend our understanding of the genetic basis of anger and hostility by showing that newly characterized HTR1B haplotypes, particularly those with rs13212041, which modulates microRNA‐mediated regulation of HTR1B expression, may have important implications for aggression‐related phenotypes among young men.

Many apples a day keep the blues away--daily experiences of negative and positive affect and food consumption in young adults.

OBJECTIVES Prior research has focused on the association between negative affect and eating behaviour, often utilizing laboratory or cross-sectional study designs. These studies have inherent limitations, and the association between positive affect and eating behaviour remains relatively unexplored. Therefore, the objective of this study was to investigate the bidirectional relationships between daily negative and positive affective experiences and food consumption in a naturalistic setting among healthy young adults. DESIGN Daily diary study across 21 days (microlongitudinal, correlational design). METHODS A total of 281 young adults with a mean age of 19.9 (± 1.2) years completed an Internet-based daily diary for 21 consecutive days. Each day they reported their negative and positive affect, and their consumption of five specific foods. Hierarchical linear modelling was used to test same-day associations between daily affect and food consumption, and next-day (lagged) associations to determine directionality. Moderating effects of BMI and gender were also examined in exploratory analyses. RESULTS Analyses of same-day within-person associations revealed that on days when young adults experienced greater positive affect, they reported eating more servings of fruit (p = .002) and vegetables (p < .001). Results of lagged analysis showed that fruits and vegetables predicted improvements in positive affect the next day, suggesting that healthy foods were driving affective experiences and not vice versa. Meaningful changes in positive affect were observed with the daily consumption of approximately 7-8 servings of fruit or vegetables. CONCLUSIONS Eating fruit and vegetables may promote emotional well-being among healthy young adults.

On carrots and curiosity: eating fruit and vegetables is associated with greater flourishing in daily life.

OBJECTIVES Our aim was to determine whether eating fruit and vegetables (FV) is associated with other markers of well-being beyond happiness and life satisfaction. Towards this aim, we tested whether FV consumption is associated with greater eudaemonic well-being - a state of flourishing characterized by feelings of engagement, meaning, and purpose in life. We also tested associations with two eudaemonic behaviours - curiosity and creativity. DESIGN Daily diary study across 13 days (micro-longitudinal, correlational design). METHODS A sample of 405 young adults (67% women; mean age 19.9 [SD 1.6] years) completed an Internet daily diary for 13 consecutive days. Each day, participants reported on their consumption of fruit, vegetables, sweets, and chips, as well as their eudaemonic well-being, curiosity, creativity, positive affect (PA), and negative affect. Between-person associations were analysed on aggregated data. Within-person associations were analysed using multilevel models controlling for weekday and weekend patterns. RESULTS Fruit and vegetables consumption predicted greater eudaemonic well-being, curiosity, and creativity at the between- and within-person levels. Young adults who ate more FV reported higher average eudaemonic well-being, more intense feelings of curiosity, and greater creativity compared with young adults who ate less FV. On days when young adults ate more FV, they reported greater eudaemonic well-being, curiosity, and creativity compared with days when they ate less FV. FV consumption also predicted higher PA, which mostly did not account for the associations between FV and the other well-being variables. Few unhealthy foods (sweets, chips) were related to well-being except that consumption of sweets was associated with greater curiosity and PA at the within-person level. Lagged data analyses showed no carry-over effects of FV consumption onto next-day well-being (or vice versa). CONCLUSIONS Although these patterns are strictly correlational, this study provides the first evidence that FV consumption may be related to a broader range of well-being states that signal human flourishing in early adulthood. Statement of contribution What is already known on this subject? There is growing evidence that a diet rich in fruits and vegetables (FV) is related to greater happiness, life satisfaction, and positive affect. These associations are not entirely explained by demographic or health variables including socio-economic status, exercise, smoking, and body mass index (BMI). Recent experimental and daily diary research suggests that FV consumption may be a causal factor in promoting states of positive well-being. Research has examined the links between FV consumption and hedonic well-being - whether people feel good (vs. bad) and satisfied-but has not addressed links between FV consumption and eudaemonic well-being- whether people feel engaged and experience their lives as meaningful and purposeful. What does this study add? It provides the first evidence that eating FV is related to greater eudaemonic well-being in a naturalistic setting. Eating FV was also related to greater self-reported curiosity and creativity. FV consumption may underlie a broad range of experiences that signal flourishing. Future randomised controlled trials of FV should include measures of eudaemonic well-being as outcome variables.

Effects of Intensive Mobile Happiness Reporting in Daily Life

Does intensive focus on happiness change the naturalistic experience of happiness over time? In a 2-week text-messaging experiment, young adult participants (n = 162) reported their current happiness 1, 3, or 6 times daily. Examination of temporal changes in momentary happiness over time showed no group differences, suggesting little evidence for reactivity overall. However, the effects were moderated by current depressive symptoms and neuroticism and to a lesser extent by self-esteem (trend only) and not by trait happiness. Individuals higher in depressive symptoms or neuroticism showed decreased momentary happiness over time with more frequent reporting, whereas individuals lower in depressive symptoms or neuroticism showed the opposite pattern with increased momentary happiness over time with more frequent reporting. Effects for self-esteem were similar but did not reach statistical significance. Findings suggest that intensive happiness reporting through mobile technology may be aversive or beneficial depending upon the negative emotional disposition of individuals.