Sweet-liking is associated with transformation of heavy drinking into alcohol-related problems in young adults with high novelty seeking.

BACKGROUND: We tested the hypothesis that high novelty seeking (NS) (a trait that promotes experimentation) and sweet-liking (SL) (a phenotype that may reflect processing of hedonic stimuli) act independently and synergistically to increase the risk of having alcohol-related problems in young adults. METHODS: A sample of 163 young adults, ages 18 to 26, was recruited and balanced for gender and evidence for presence of alcohol problems to yield 150 evaluable participants. NS was evaluated using the Tridimensional Personality Questionnaire. Pleasurable response to sweet taste was tested to identify sweet-likers and sweet-dislikers. Alcohol use and problems were assessed by the Alcohol Use Disorders Identification Test and the Rutgers Alcohol Problem Index. RESULTS: NS, but not SL, was positively and significantly associated with alcohol consumption and alcohol problems; however, the effect of NS on alcohol problems was significantly enhanced in the presence of the SL phenotype, thus showing a strong synergistic interaction. The combination of SL and high NS was associated with increased odds of having alcohol problems -20.64 (95% CI: -89.98, 4.74) compared to those with low NS and sweet-disliking. Other combinations did not produce such odds ratios. SL and low NS showed OR = 1.88 (95% CI 0.44, 7.99), and sweet-dislikers and high novelty seekers had OR = 4.07 (95%, CI 1.01, 16.46). CONCLUSIONS: These results support and extend our hypothesis that as clinically distinct phenotypes, high NS and the SL phenotype are associated with risk of alcohol-related problems. High NS is associated with the use of alcohol, and the presence of the SL phenotype appears to bias an individual to alcohol problems once alcohol use is initiated. Understanding the biology and phenomenology of these phenotypes will allow a more complete picture of the processes that lead to alcohol problems.

Effects of reducing the frequency and duration criteria for binge eating on lifetime prevalence of bulimia nervosa and binge eating disorder: implications for DSM-5.

OBJECTIVE: We assessed the impact of reducing the binge eating frequency and duration thresholds on the diagnostic criteria for bulimia nervosa (BN) and binge eating disorder (BED). METHOD: We estimated the lifetime population prevalence of BN and BED in 13,295 female twins from the Swedish Twin study of Adults: Genes and Environment employing a range of frequency and duration thresholds. External validation (risk to cotwin) was used to investigate empirical evidence for an optimal binge eating frequency threshold. RESULTS: The lifetime prevalence estimates of BN and BED increased linearly as the frequency criterion decreased. As the required duration increased, the prevalence of BED decreased slightly. Discontinuity in cotwin risk was observed in BN between at least four times per month and at least five times per month. This model could not be fit for BED. DISCUSSION: The proposed changes to the DSM-5 binge eating frequency and duration criteria would allow for better detection of binge eating pathology without resulting in a markedly higher lifetime prevalence of BN or BED.

Semen characteristics and artificial insemination in rockhopper penguins (Eudyptes chrysocome chrysocome).

This work was performed as part of a multi-year study to determine the cause of the low fertility in captive rockhopper penguins (Eudyptes chrysocome chrysocome) and attempt to increase the fertility through artificial insemination (AI). Semen collection and characterization was performed on 14 male rockhopper penguins. The samples were evaluated for volume, sperm concentration, and sperm quality (motility, forward motility, viability, and morphology). There was a large variation between individuals and between collections for each individual. Mean volume of ejaculate was 0.24 ml. Mean concentration was 47.09 × 10(6) sperm/ml. Mean number of sperm per collection was 6.57 × 10(6). The mean motility was 49.4%. Mean forward motility was 1.7. Mean percentage of living sperm was 88.9%. Mean percentage of sperm with normal morphology was 69.4%. AI was performed on a total of 10 females using pooled semen samples. The birds were also allowed to naturally mate. Ten eggs were laid and three fertile eggs were produced, one of them hatched but died within 24 hr. Paternity testing was performed using 12 microsatellite loci, but unfortunately due to insufficient variability, the paternity of the chick and two embryos could not be determined.

Redefining phenotypes in eating disorders based on personality: a latent profile analysis.

To conduct a latent profile analysis (LPA) in eating disorder (ED) patients using temperament and character (TCI-R) measures as indicators. 1312 ED patients including those with anorexia nervosa (AN), bulimia nervosa (BN) and EDNOS were assessed. The final LPA solution was validated using demographics, clinical variables, ED symptomatology (EDI-2) and impulsive behaviors. The best-fitting model consisted of a six-profile solution using the seven subscales of the TCI-R. These profiles were labeled: "self-focused", "inhibited", "average", "impulsive", "adaptive" and "maladaptive". Validation analyses indicated that the "inhibited" and "maladaptive" profiles generally presented with the highest values for ED symptomatology and impulsive behaviors. Whereas high levels of Harm Avoidance and low levels of Novelty Seeking and Persistence characterized the "inhibited" profile, the "maladaptive" profile presented with low levels of Reward Dependence, Self-Directedness and Cooperativeness. The most favorable results on the other hand were exhibited by the "adaptive" profile, characterized by high scores on Reward Dependence, Self-Directedness, Cooperativeness and low levels on Novelty Seeking. Finally, when our six-profile solution was compared with the DSM-IV ED diagnoses, significant differences among profiles and ED diagnoses were observed. Our study shows that ED patients can be meaningfully grouped according to temperament and character.

Life beyond the eating disorder: education, relationships, and reproduction.

OBJECTIVE: We investigated the sociodemographic characteristics in women with and without lifetime eating disorders. METHOD: Participants were from a multisite international study of eating disorders (N = 2,096). Education level, relationship status, and reproductive status were examined across eating disorder subtypes and compared with a healthy control group. RESULTS: Overall, women with eating disorders were less educated than controls, and duration of illness and age of onset were associated with educational attainment. Menstrual status was associated with both relationship and reproductive status, but eating disorder subtypes did not differ significantly from each other or from healthy controls on these dimensions. DISCUSSION: Differences in educational attainment, relationships, and reproduction do exist in individuals with eating disorders and are differentially associated with various eating disorder symptoms and characteristics. These data could assist in educating patients and family members about long-term consequences of eating disorders.

Disordered eating and substance use among a female sample of Mexican adolescents.

The relation between disordered eating and substance use was examined among Mexican female adolescents in a probabilistic sample of 2537 high school students in central Mexico, stratified by marginalization status and migratory intensity, obtained during 2006 ?2007 school year. The Brief Disordered Eating Questionnaire and the World Health Organization and United Nations Division of Narcotic Drugs recommendations for substance use assessments were used. Prevalence and odds ratios for disordered eating and substance use items were calculated separately across low and high marginalization groups. Study's implications and limitations are noted, as well as future research and prevention strategies are suggested.

Association of candidate genes with phenotypic traits relevant to anorexia nervosa.

This analysis is a follow-up to an earlier investigation of 182 genes selected as likely candidate genetic variations conferring susceptibility to anorexia nervosa (AN). As those initial case-control results revealed no statistically significant differences in single nucleotide polymorphisms, herein, we investigate alternative phenotypes associated with AN. In 1762 females, using regression analyses, we examined the following: (i) lowest illness-related attained body mass index; (ii) age at menarche; (iii) drive for thinness; (iv) body dissatisfaction; (v) trait anxiety; (vi) concern over mistakes; and (vii) the anticipatory worry and pessimism versus uninhibited optimism subscale of the harm avoidance scale. After controlling for multiple comparisons, no statistically significant results emerged. Although results must be viewed in the context of limitations of statistical power, the approach illustrates a means of potentially identifying genetic variants conferring susceptibility to AN because less complex phenotypes associated with AN are more proximal to the genotype and may be influenced by fewer genes.

Substance use disorders in women with anorexia nervosa.

OBJECTIVE: We examined prevalence of substance use disorders (SUD) in women with: (1) anorexia nervosa (AN) restricting type (RAN); (2) AN with purging only (PAN); (3) AN with binge eating only (BAN); and (4) lifetime AN and bulimia nervosa (ANBN). Secondary analyses examined SUD related to lifetime purging behavior and lifetime binge eating. METHOD: Participants (N = 731) were drawn from the International Price Foundation Genetic Studies. RESULTS: The prevalence of SUD differed across AN subtypes, with more in the ANBN group reporting SUD than those in the RAN and PAN groups. Individuals who purged were more likely to report substance use than those who did not purge. Prevalence of SUD differed across lifetime binge eating status. DISCUSSION: SUD are common in AN and are associated with bulimic symptomatology. Results underscore the heterogeneity in AN, highlighting the importance of screening for SUD across AN subtypes.

Association study of 182 candidate genes in anorexia nervosa.

We performed association studies with 5,151 SNPs that were judged as likely candidate genetic variations conferring susceptibility to anorexia nervosa (AN) based on location under reported linkage peaks, previous results in the literature (182 candidate genes), brain expression, biological plausibility, and estrogen responsivity. We employed a case-control design that tested each SNP individually as well as haplotypes derived from these SNPs in 1,085 case individuals with AN diagnoses and 677 control individuals. We also performed separate association analyses using three increasingly restrictive case definitions for AN: all individuals with any subtype of AN (All AN: n = 1,085); individuals with AN with no binge eating behavior (AN with No Binge Eating: n = 687); and individuals with the restricting subtype of AN (Restricting AN: n = 421). After accounting for multiple comparisons, there were no statistically significant associations for any individual SNP or haplotype block with any definition of illness. These results underscore the importance of large samples to yield appropriate power to detect genotypic differences in individuals with AN and also motivate complementary approaches involving Genome-Wide Association (GWA) studies, Copy Number Variation (CNV) analyses, sequencing-based rare variant discovery assays, and pathway-based analysis in order to make up for deficiencies in traditional candidate gene approaches to AN.

Semen collection and characterization in rockhopper penguins (Eudyptes chrysocome chrysocome).

Low egg fertility and hatchability is a common problem in captive populations of rockhopper penguins (Eudyptes chrysocome chrysocome). These conditions make sustaining a captive population challenging. A method for collecting and evaluating semen from rockhopper penguins was developed to assist in the evaluation of low egg fertility found in one captive population. Six adult male rockhopper penguins were conditioned to allow semen collection once a week from the start of breeding season until ejaculates no longer contained sperm. A total of 59 ejaculates was collected between 17 September and 31 December 2004. Forty-five of these samples were evaluated for volume, pH, sperm concentration, and sperm quality (motility, viability, and morphology). There was a large variation between individuals and between collections for each individual. The mean motility was 34.5% (+/- 22%). Mean volume of ejaculate was 0.23 ml (+/- .31 ml). Mean concentration was 16.9 x 10(6) sperm/ml (+/- 48.7 x 10(6) sperm/ml). Mean number of sperm per collection was 1.7 x 10(6) (+/- 4.2 x 10(6)). Mean percentage of living sperm was 82.9% (+/- 18.1%). Mean percentage of sperm with normal morphology was 82.1% (+/- 18.8%). Mean pH was 6.47 (+/- 0.49). During this season, only one of these males paired with a female. The pair produced one fertile egg, but the embryo died early in incubation. Male rockhopper penguins had low sperm concentration and low motility indicating that low male fertility may be contributing to the poor egg fertility rate. This work represents the first step in an ongoing study to improve captive breeding of rockhopper penguins.

Self-concept and body image in persons who are spinal cord injured with and without lower limb amputation.

Spinal cord injury (SCI) requires considerable psychological adjustment to physical limitations and complications. One particularly severe complication of SCI is foot skin breakdown, which can result in lower limb amputation. Relative to SCI adjustment, amputation may produce one of two psychological outcomes: (a.) the fragile self-concept of a person with SCI may be reduced further by limb amputation, or (b.) amputation of a diseased, nonfunctional limb may be associated with restored health and improved self-concept. To better understand the effects of amputation, 26 males with SCI, 11 of whom had a lower limb amputation, were administered the Tennessee Self-Concept Scale (TCS) and the Personal Body Attractiveness Scale (PBAS). The study revealed that persons with SCI with amputation had higher Physical and Total self-concept scores on the TSCS, showing a slightly more positive self-concept. On the PBAS, although there were no significant differences in the scores for the legs, ankles, or feet, the persons with SCI with amputation had higher score on the Satisfaction subscale, indicating a slightly greater satisfaction with their thigh in their body image. Implications for future study include replication with larger sample sizes, inclusion of women in the sample, and a longitudinal study. Several nursing interventions are identified.

A behavioral-genetic investigation of bulimia nervosa and its relationship with alcohol use disorder.

Bulimia nervosa (BN) and alcohol use disorder (AUD) frequently co-occur and may share genetic factors; however, the nature of their association is not fully understood. We assessed the extent to which the same genetic and environmental factors contribute to liability to BN and AUD. A bivariate structural equation model using a Cholesky decomposition was fit to data from 7241 women who participated in the Swedish Twin study of Adults: Genes and Environment. The proportion of variance accounted for by genetic and environmental factors for BN and AUD and the genetic and environmental correlations between these disorders were estimated. In the best-fitting model, the heritability estimates were 0.55 (95% CI: 0.37; 0.70) for BN and 0.62 (95% CI: 0.54; 0.70) for AUD. Unique environmental factors accounted for the remainder of variance for BN. The genetic correlation between BN and AUD was 0.23 (95% CI: 0.01; 0.44), and the correlation between the unique environmental factors for the two disorders was 0.35 (95% CI: 0.08; 0.61), suggesting moderate overlap in these factors. The findings from this investigation provide additional support that some of the same genetic factors may influence liability to both BN and AUD.

Anorexia nervosa and generalized anxiety disorder: further explorations of the relation between anxiety and body mass index.

We explore comorbidity of anorexia nervosa (AN) and generalized anxiety disorder (GAD) and their relation with body mass index (BMI) and evaluate the presence of fasting and excessive exercise which both have anxiolytic and weight loss effects. All participants were female: 32 with AN only, 607 with GAD only, 22 with AN and GAD (AN+GAD), and 5424 with no history of AN or GAD (referent) from the Swedish Twin study of Adults: Genes and Environment (STAGE). Lowest adult BMI differed significantly (p<.001) and was lower in those with AN+GAD than those with AN only (p<.029). Those with AN+GAD were most likely to endorse fasting and excessive exercise, followed by women with AN only, women with GAD only, and the referent. Comorbid AN and GAD may be a particularly pernicious presentation influencing both BMI and proclivity to engage in behaviors such as fasting and exercise that serve both weight loss and anxiolytic goals.

Understanding the relation between anorexia nervosa and bulimia nervosa in a Swedish national twin sample.

BACKGROUND: We present a bivariate twin analysis of anorexia nervosa and bulimia nervosa to determine the extent to which shared genetic and environmental factors contribute to liability to these disorders. METHOD: Focusing on females from the Swedish Twin study of Adults: Genes and Environment (n = 7000), we calculated heritability estimates for narrow and broad anorexia nervosa and bulimia nervosa and estimated their genetic correlation. RESULTS: In the full model, the heritability estimate for narrow anorexia nervosa (AN) was (a(2) = .57; 95% confidence interval [CI]: .00-.81) and for narrow bulimia nervosa (BN) (a(2) = .62; 95% CI: .08-.70), with the remaining variance accounted for by unique environmental factors. Shared environmental factors estimates were (c(2) = .00; 95% CI: .00-.67) for AN and (c(2) = .00; 95% CI: .00-.40) for BN. Moderate additive genetic (.46) and unique environmental (.42) correlations between AN and BN were observed. Heritability estimates for broad AN were lower (a(2) = .29; 95% CI: .04-.43) than for narrow AN, but estimates for broad BN were similar to narrow BN. The genetic correlation for broad AN and BN was .79, and the unique environmental correlation was .44. CONCLUSIONS: We highlight the contribution of additive genetic factors to both narrow and broad AN and BN and demonstrate a moderate overlap of both genetic and unique environmental factors that influence the two conditions. Common concurrent and sequential comorbidity of AN and BN can in part be accounted for by shared genetic and environmental influences on liability although independent factors also operative.

Shared and unique genetic and environmental influences on binge eating and night eating: a Swedish twin study.

We applied twin methodology to female and male twin pairs to further understand the nature of the relation between two behaviors associated with eating disorders-binge eating (BE) and night eating (NE) in an effort to determine the extent of overlap of genetic and environmental factors influencing liability to these behaviors. We calculated heritability estimates for males and females for each behavior and applied bivariate twin modeling to the female data to estimate the genetic and environmental correlation between these two traits. Data on BE and NE were derived from the Swedish Twin study of Adults: Genes and Environment (STAGE) of the Swedish Twin Registry (STR; N=11,604). Prevalence estimates revealed sex differences with females more likely to endorse BE and males more likely to endorse NE. In males, we were only able to estimate univariate heritabilities due to small sample sizes: The heritability for BE was 0.74 [95% CI=(0.36, 0.93)] and for NE was 0.44 [95% CI=(0.24, 0.61)]. The best fitting bivariate model for females included additive genetic and unique environmental factors as well as the genetic correlation between BE and NE. Heritability estimates were 0.70 [95% CI=(0.26, 0.77)] for BE and 0.35 [95% CI=(0.17, 0.52)] for NE. The genetic correlation, 0.66 [95% CI=(0.48, 0.96)] suggests considerable overlap in the genetic factors influencing liability to BE and NE. In females, there is considerable overlap in the genetic factors that contribute to these traits, but the incomplete overlap allows for the influence of independent genetic and environmental factors as well. BE and NE in females are therefore best conceptualized as related but not identical traits.

The Genetics of Anorexia Nervosa: Current Findings and Future Perspectives.

Anorexia nervosa is a perplexing illness with the highest mortality rate of any psychiatric disease. In this paper, we review the genetic research on anorexia nervosa (AN). Family studies have demonstrated that anorexia nervosa is familial, and twin studies have indicated that additive genetic factors contribute to the familial aggregation. Molecular genetic research, including genomewide linkage and case control association studies, have not been successful in identifying DNA variants that are unequivocally involved in the etiology of AN. We provide a critical appraisal of these studies and discuss methodological issues that may be implicated in conflicting results. Furthermore, we discuss issues relevant to genetic research such as the importance of phenotypic refinement, the use of endophenotypes, and the implications for nosology and genetic analysis. Finally, the future of genetic research for AN is discussed in terms of genomewide association studies (GWAS) and the need for establishing large samples.