Smoking and genetic risk variation across populations of European, Asian, and African American ancestry--a meta-analysis of chromosome 15q25.

Recent meta-analyses of European ancestry subjects show strong evidence for association between smoking quantity and multiple genetic variants on chromosome 15q25. This meta-analysis extends the examination of association between distinct genes in the CHRNA5-CHRNA3-CHRNB4 region and smoking quantity to Asian and African American populations to confirm and refine specific reported associations. Association results for a dichotomized cigarettes smoked per day phenotype in 27 datasets (European ancestry (N = 14,786), Asian (N = 6,889), and African American (N = 10,912) for a total of 32,587 smokers) were meta-analyzed by population and results were compared across all three populations. We demonstrate association between smoking quantity and markers in the chromosome 15q25 region across all three populations, and narrow the region of association. Of the variants tested, only rs16969968 is associated with smoking (P < 0.01) in each of these three populations (odds ratio [OR] = 1.33, 95% CI = 1.25-1.42, P = 1.1 × 10(-17) in meta-analysis across all population samples). Additional variants displayed a consistent signal in both European ancestry and Asian datasets, but not in African Americans. The observed consistent association of rs16969968 with heavy smoking across multiple populations, combined with its known biological significance, suggests rs16969968 is most likely a functional variant that alters risk for heavy smoking. We interpret additional association results that differ across populations as providing evidence for additional functional variants, but we are unable to further localize the source of this association. Using the cross-population study paradigm provides valuable insights to narrow regions of interest and inform future biological experiments.

Reliability of informant ratings and spouse similarity based on the Temperament and Character Inventory.

A cohort of 136 Swedish spouse pairs rated themselves and each other with the Temperament and Character Inventory. The data allowed assessment of the reliability of ratings by knowledgeable informants compared to self-rating for this personality test. The reliability of the informant rating was in the expected range, with an average correlation of .58. Agreement was slightly higher for the Temperament dimensions than for the Character dimensions. Additionally, the design allowed evaluation of the similarity between husbands and wives across the seven dimensions measured by the TCI. Correlations between spouses in self-reports were very low for Temperament, with only Harm Avoidance having a statistically significant correlation (.22, p < .05). On the other hand, all three Character dimensions were significantly correlated. These results support the conceptualization of Temperament and Character as separate components of personality. The results are consistent with previous reports on the personality of spouse pairs.

Exploring temperament and character traits in medical students; a new approach to increase the rural workforce.

BACKGROUND: This study explored temperament and character traits in medical students to identify the possible predictive value of these traits to students with varying levels of intention to pursue rural medicine. This work is the precursor to a better understanding of personality traits associated with medical disciplines within specific environments such as rural medicine. AIMS: The long term aim is to increase the recruitment of students who are best suited, and choose to practice in rural locations. METHODS: Medical students (272) completed a demographic survey and the Temperament and Character Inventory (TCI-R 140) to identify levels of the seven basic dimensions of temperament and character. Multivariate statistics explored differences between students' TCI levels based on gender, rural origin and level of intention to pursue rural medicine. RESULTS: Analysis showed only main effects and confirmed significant differences in certain TCI dimensions between students with a high compared to a low or medium intention to practice rural medicine and between males and females. CONCLUSIONS: Preliminary findings suggest that certain temperament and character traits may be related to interest in rural medicine however the efficacy of assessing personality traits as an adjunct to medical school training and career counselling remains uncertain.

Screening for alcohol problems: an epidemiological perspective and implications for primary care.

In a random sample of 917 adults from the general population greater St. Louis, 19.6% of respondents screened positive for "probable alcohol abuse or dependence". Screening positive is indicative of unhealthy drinking patterns. The regular use of such instruments in primary care settings could facilitate patient-physician communication regarding alcohol problems, thereby improving detection and leading to greater utilization of appropriate medical treatment, including pharmacotherapy.

Discrepancies in estimates of prevalence and correlates of substance use and disorders between two national surveys.

AIM: To assess the degree to which methodological differences might influence estimates of prevalence and correlates of substance use and disorders by comparing results from two recent surveys administered to nationally representative US samples. METHODS: Post-hoc comparison of data from the 2002 National Survey on Drug Use and Health (NSDUH) with data from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) administered in 2001-02. RESULTS: Prevalence estimates for all substance use outcomes were higher in the NSDUH than in the NESARC; ratios of NSDUH to NESARC prevalences ranged from 2.1 to 5.7 for illegal drug use outcomes. In the NSDUH, past-year substance use disorder (SUD) prevalence estimates were higher for cocaine and heroin, but were similar to NESARC estimates for alcohol, marijuana and hallucinogens. However, prevalence estimates for past-year SUD conditional on past-year use were substantially lower in the NSDUH for marijuana, hallucinogens and cocaine. Associations among drug and SUD outcomes were substantially higher in the NESARC. Total SUD prevalence did not differ between surveys, but estimates for blacks and Hispanics were higher in the NSDUH. CONCLUSION: A number of methodological variables might have contributed to such discrepancies; among plausible candidates are factors related to privacy and anonymity, which may have resulted in higher use estimates in the NSDUH, and differences in SUD diagnostic instrumentation, which may have resulted in higher SUD prevalence among past-year substance users in the NESARC.

Can personality assessment predict future depression? A twelve-month follow-up of 631 subjects.

BACKGROUND: Personality assessment provides a description of a person's fundamental emotional needs and of the higher cognitive processes that modulate thoughts, feelings, and behavior. Prior studies by us examined personality and mood at the same time. Assessing personality may allow prediction of mood changes over time in a longitudinal study, as described in earlier prospective studies by Paula Clayton and others. METHOD: A group of 631 adults representative of the general population completed the Temperament and Character Inventory (TCI) and Center for Epidemiological Studies depression scale (CES-D) at baseline and one year later. RESULTS: TCI scores at baseline accounted for gender differences in levels of depression. TCI personality scores were strongly stable (range in r=.78 to .85 for each of seven dimensions) whereas mood was only moderately stable (r=.62) over the twelve-month follow-up. Baseline personality scores (particularly high Harm Avoidance and low Self-Directedness) explained 44% of the variance in the change in depression. Baseline levels and changes in Harm Avoidance and Self-Directedness explained 52% of the variance in the change in depression at follow-up. LIMITATIONS: The follow-up sample was representative of the target population except for slightly lower Novelty Seeking scores. CLINICAL RELEVANCE: Observable personality levels strongly predict mood changes. Personality development may reduce vulnerability to future depression.

Prevalence and predictors of pathological gambling: results from the St. Louis personality, health and lifestyle (SLPHL) study.

OBJECTIVES: We report the prevalence of and risk and protective factors for DSM-IV sub-threshold gambling (1-4 criteria) and pathological gambling disorder (PGD; 5-10 criteria) in a non-clinical household sample of St. Louis area gamblers. METHODS: Of the 7689 individuals contacted via Random Digit Dialing, 3292 were screened eligible. Of these, 1142 from households in 6 contiguous regions in Missouri and Illinois consented to participate and were mailed a St. Louis Area Personality, Health, and Lifestyle (SLPHL) Survey. RESULTS: Post-stratification weighted data (n=913) indicate lifetime prevalence rates of 12.4% sub-threshold and 2.5% PGD (conditional prevalence=21.5% and 4.3% respectively). Risk and protective factors for gambling severity varied in the sample. CONCLUSIONS: Targeted prevention messages are warranted specifically for gamblers of varying risk for PGD.

Personality and depressive symptoms: a multi-dimensional analysis.

BACKGROUND: The relationship of temperamental aspects of personality to symptoms of depression in a community-based sample of 804 individuals was examined using a multi-dimensional approach to account for heterogeneity in symptom patterns. METHOD: The Temperament and Character Inventory (TCI) was used to assess personality and the Center for Epidemiologic Studies Depression scale (CES-D) was used to measure depressive symptoms. Canonical correlation analysis was used to relate CES-D item combinations to temperament traits in multiple dimensions. The relationships between temperament and various conditions correlated with depression were examined using logistic regression. RESULTS: Temperamental aspects of personality are related not only to total CES-D score, but also to the patterns of CES-D items endorsed by subjects. High Harm Avoidance is related to total CES-D score; high Reward Dependence combined with high Persistence is associated with restless sleep and subjective symptoms; high Reward Dependence combined with low Persistence is negatively associated with appetite loss and low energy; high Novelty Seeking is related to maintenance of positive affect and inability to concentrate. High Novelty Seeking is also associated with past suicide attempts, after adjusting for total CES-D score. LIMITATIONS: Cross-sectional data prevent analysis of causation; the severest cases of clinical depression may not be represented in a general population sample. Depressive symptoms are self-reported. CONCLUSION: Substantial differences in level of symptoms and in symptom patterns exist among individuals in a continuum of depressed states and those differences are partially explained by temperament traits.

Exploring the temperament and character traits of rural and urban doctors.

CONTEXT: Australia shares many dilemmas with North America regarding shortages of doctors in rural and remote locations. This preliminary study contributes to the establishment of a psychobiological profile for rural doctors by comparing temperament and character traits with an urban cohort. PURPOSE: The aim was to compare the individual levels and combinations of temperament (mildly heritable and stable) and character (developmental and modifiable) traits of rural and urban general practitioners (GPs). METHODS: Rural (n = 120) and urban (n = 94) GPs completed a demographic questionnaire and the TCI-R 140 to identify levels of the 7 basic dimensions of temperament and character. These are Novelty Seeking (NS), Harm Avoidance (HA), Reward Dependence (RD), Persistence (PS), Self-Directedness (SD), Cooperativeness (CO), and Self-Transcendence (ST). FINDINGS: Preliminary results show rural GPs were higher in the temperament traits of NS and lower in HA compared with the urban sample. All female GPs were higher in RD and CO compared with all males, and all older GPs (over 55 years) were lower in RD compared with all younger GPs. CONCLUSIONS: This preliminary work may be the precursor to a new approach for the recruitment and retention of rural doctors through a greater awareness of personality traits conducive to the rural workforce. Further work may help inform appropriate policies to attract and retain this workforce and be a useful adjunct to the counseling of students interested in rural medicine by providing a better understanding of "what it takes" to be a rural doctor.

Prevalence and correlates of binge eating disorder in a community sample.

OBJECTIVE: Diagnostic criteria for binge eating disorder (BED) appear in Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition as "criteria for further study." Few epidemiological studies of BED have been conducted. Our aim was to describe the prevalence and correlates of BED, as assessed by the Patient Health Questionnaire (PHQ) in a community sample. METHOD: Descriptive epidemiology from a survey of 910 randomly ascertained participants residing in the greater metropolitan area of St Louis, Mo. RESULTS: Sixty individuals (6.6%) screened positive for current BED, as assessed by the PHQ (BED+). Men were as likely to screen positive as women. BED+ subjects were at substantially elevated odds for depression, generalized anxiety disorder, panic attacks, and past suicide attempts; individuals with obesity who screened negative for BED (BED-) were not at elevated odds for these syndromes. BED+ subjects, but not other obese individuals, exhibited substantially lower scores on measures of mental health-related quality of life. Personality traits associated with BED symptoms included high Novelty Seeking, high Harm Avoidance, and low Self-directedness. Personality and psychiatric profiles in obese, BED- individuals were closer to those for normal-weight, BED- individuals, suggesting that BED is distinct from typical obesity. BED+ subjects reported mean body mass index of 34.1, more than 6 units above BED- subjects. CONCLUSION: PHQ-BED criteria are associated with substantial impairment, psychiatric comorbidity, and obesity and effectively discriminate obese individuals with psychological problems from obese subjects without similar problems. BED may be considerably more prevalent than other eating disorders and equally prevalent among men and women.

Diet and personality: associations in a population-based sample.

BACKGROUND: Large portions of the population of the United States of America fail to follow dietary recommendations. Psychological factors may contribute to non-adherence. OBJECTIVE: Establish the associations between heritable personality styles, attitudes towards food, and habitual eating behavior. DESIGN: Variables were assessed by questionnaire in a population-based sample of 629 subjects. Associations were established using correlation and regression analysis, taking gender, demographic, lifestyle and other factors into account. RESULTS: Differences in personality style were reflected in diet. For example, hostility and anxiety-proneness was associated with greater likelihood to continue eating when satiated, while sociability and low impulsivity correlated with greater monitoring and control of dietary intake and body weight. Immaturity, aloofness, self-consciousness and self-gratification were associated with greater susceptibility to hunger and lack of persistence with increased snack and alcohol consumption. These associations differed for the sexes and were stronger for attitudes towards food than actual eating behavior. Taking other factors into account reduced the number of significant associations between diet and personality, particularly for habitual eating behavior. CONCLUSIONS: Associations exist between personality and diet. However, the strength of these associations is influenced by demographic, lifestyle and other factors. These findings have implications for future studies and efforts aimed at changing unhealthy dietary habits.

Personality as a mediator of demographic risk factors for suicide attempts in a community sample.

The aim of this study was to determine whether personality might partially explain associations between sociodemographic factors and self-reported suicide attempts. This analysis was motivated by reports that certain personality traits are logical targets for intervention, whereas sociodemographic characteristics are not generally modifiable. Data were from a postal survey sent to community residents who were previously selected at random (N = 912). Age, gender, health-insurance status, education, self-reported health, and marital history were identified as relevant sociodemographic predictors of having made one or more lifetime suicide attempts. Risk associated with each of these variables was mediated by the personality traits of self-directedness (SD) and harm avoidance (HA). In a multiple logistic-regression analysis constrained to sociodemographic predictors, only young age, female sex, poor self-reported health, and Medicaid status remained as predictors of suicide attempts. When personality factors were added to the model, all of the sociodemographic predictors except Medicaid status were rendered nonsignificant or marginally significant. Risk associated with gender was primarily related to HA, risk associated with poor self-reported health was mediated by both HA and SD, and the risk associated with young age was primarily mediated by SD; the last was the largest mediation effect observed. In contrast, risk associated with receipt of Medicaid, presumed to indicate low socioeconomic status, was not mediated by personality. We conclude that risk associated with certain nonmodifiable demographic factors is often mediated by potentially modifiable intrapersonal factors, such as SD.

Relationship between specialty choice and medical student temperament and character assessed with Cloninger Inventory.

BACKGROUND: Multiple variables affect medical specialty choice, including temperament, sociodemographic factors, and personal experiences. Many studies address specific variables for specific specialties, but few assess the relative impact of each factor. PURPOSE: To identify the relative influence of temperament in choosing a specialty. METHODS: A sociodemographic and personal experiences questionnaire and a 240-question temperament and character inventory was distributed to 682 medical students. Their scores for 6 medical specialties were examined using analyses of variance, multivariate analyses of variance, and discriminant analysis. RESULTS: Students choosing surgery, emergency medicine, and obstetrics and gynecology were higher on novelty seeking than other students. Future surgeons were lower in harm avoidance and reward dependence (RD) than the others. Students choosing primary care specialties, emergency medicine, and obstetrics and gynecology were all high on RD; with pediatrics being highest. Students differed from college students, the women differed from the men, and the Asian Americans differed from the other groups. CONCLUSION: The implications of these findings are discussed for career counseling and future research.