Personality as an intermediate phenotype for genetic dissection of alcohol use disorder.

Genetic and environmental interactive influences on predisposition to develop alcohol use disorder (AUD) account for the high heterogeneity among AUD patients and make research on the risk and resiliency factors complicated. Several attempts have been made to identify the genetic basis of AUD; however, only few genetic polymorphisms have consistently been associated with AUD. Intermediate phenotypes are expected to be in-between proxies of basic neuronal biological processes and nosological symptoms of AUD. Personality is likely to be a top candidate intermediate phenotype for the dissection of the genetic underpinnings of different subtypes of AUD. To date, 38 studies have investigated personality traits, commonly assessed by the Cloninger's Tridimensional Personality Questionnaire (TPQ) or Temperament and Character Inventory (TCI), in relation to polymorphisms of candidate genes of neurotransmitter systems in alcohol-dependent patients. Particular attention has been given to the functional polymorphism of the serotonin transporter gene (5-HTTLPR), however, leading to contradictory results, whereas results with polymorphisms in other candidate monoaminergic genes (e.g., tryptophan hydroxylase, serotonin receptors, monoamine oxidases, dopamine receptors and transporter) are sparse. Only one genome-wide association study has been performed so far and identified the ABLIM1 gene of relevance for novelty seeking, harm avoidance and reward dependence in alcohol-dependent patients. Studies investigating genetic factors together with personality could help to define more homogenous subgroups of AUD patients and facilitate treatment strategies. This review also urges the scientific community to combine genetic data with psychobiological and environmental data to further dissect the link between personality and AUD.

Temperament and character profiles in bipolar I, bipolar II and major depressive disorder: Impact over illness course, comorbidity pattern and psychopathological features of depression.

BACKGROUND: Studies comparing temperament and character traits between patients with mood disorders and healthy individuals have yielded variable results. METHODS: The Temperament and Character Inventory (TCI) was administered to 101 bipolar I (BP-I), 96 bipolar II (BP-II), 123 major depressive disorder (MDD) patients, and 125 HS. A series of generalized linear models were performed in order to: (a) compare the TCI dimensions across groups; (b) test any effect of the TCI dimensions on clinical features of mood disorders; and (c) detect any association between TCI dimensions and the psychopathological features of a major depressive episode. Demographic and clinical variables were also included in the models as independent variables. RESULTS: Higher Harm Avoidance was found in BP-II and MDD, but not in BP-I. Higher Self-Transcendence was found in BP-I. Our models also showed higher Self-Directedness in HS, either vs MDD or BP-II. No association was found between any TCI dimension and the severity of symptoms. Conversely, a positive association was found between Harm Avoidance and the overall burden of depressive episodes during lifetime. LIMITATIONS: The cross-sectional design and the heterogeneity of the sample may be the main limitations of our study. CONCLUSION: In general, our sample seems to support the view of a similar profile of temperament and character between MDD and BP-II, characterized by high Harm Avoidance and low Self-Directedness. In contrast, patients with BP-I only exhibit high Self-Transcendence, having a near-normal profile in terms of Harm Avoidance or Self-Directedness.

Temperament and character traits predict future burden of depression.

BACKGROUND: Personality traits are associated with depressive symptoms and psychiatric disorders. Evidence for their value in predicting accumulation of future dysphoric episodes or clinical depression in long-term follow-up is limited, however. METHODS: Within a 15-year longitudinal study of a general-population cohort (N=751), depressive symptoms were measured at four time points using Beck׳s Depression Inventory. In addition, 93 primary care patients with DSM-IV depressive disorders and 151 with bipolar disorder, diagnosed with SCID-I/P interviews, were followed for five and 1.5 years with life-chart methodology, respectively. Generalized linear regression models were used to predict future number of dysphoric episodes and total duration of major depressive episodes. Baseline personality was measured by the Temperament and Character Inventory (TCI). RESULTS: In the general-population sample, one s.d. lower Self-directedness predicted 7.6-fold number of future dysphoric episodes; for comparison, one s.d. higher baseline depressive symptoms increased the episode rate 4.5-fold. High Harm-avoidance and low Cooperativeness also implied elevated dysphoria rates. Generally, personality traits were poor predictors of depression for specific time points, and in clinical populations. Low Persistence predicted 7.5% of the variance in the future accumulated depression in bipolar patients, however. LIMITATIONS: Degree of recall bias in life charts, limitations of statistical power in the clinical samples, and 21-79% sample attrition (corrective imputations were performed). CONCLUSION: TCI predicts future burden of dysphoric episodes in the general population, but is a weak predictor of depression outcome in heterogeneous clinical samples. Measures of personality appear more useful in detecting risk for depression than in clinical prediction.

Rasgos del temperamento y carácter en pacientescon trastorno bipolar y asociaciones con elalcoholismo o trastornos de ansiedad comórbidos / Temperament and character traits in patients with bipolar disorder and associations with comorbid alcoholism or anxiety disorders

Los rasgos de temperamento y carácter pueden determinar diferencias en las presentaciones clínicas y el desenlace del trastorno bipolar. Comparamos los rasgos de personalidad en pacientes bipolares e individuos sanos utilizando el cuestionario de temperamento y carácter (Temperament and Character Inventory [TCI]) y tratamos de verificar si la comorbilidad con el alcoholismo o los trastornos de ansiedad se asocia con rasgos específicos de la personalidad. Se comparó a 73 pacientes con trastorno bipolar, basado en los criterios del Diagnostic and Statistical Manual of Mental Disorders,4.a edición (DSM-IV), con 63 individuos sanos usando el TCI. En una segunda fase, la muestra de pacientes bipolares se dividió en subgrupos según la comorbilidad psiquiátrica que tuvieran (alcoholismo, n = 10; trastornos de ansiedad, n = 23; alcoholismo más trastornos de ansiedad, n = 21; ausencia de comorbilidad, n = 19). Los pacientes bipolares obtuvieron puntuaciones significativamente más altas que los individuos sanos en la búsqueda de novedades, evitación de riesgos y autotrascendencia y puntuaciones más bajas en autodirección y cooperación. Los pacientes bipolares con alcoholismo comórbido exclusivo obtuvieron puntuaciones significativamente más bajas que aquellos sin ninguna comorbilidad en la perseverancia. Los pacientes bipolares con trastornos de ansiedad comórbidos exclusivos obtuvieron puntuaciones significativamente más altas en evitación de riesgos y más bajas en autodirección que aquellos sin ninguna comorbilidad. Las limitaciones de este estudio son el diseño transversal y el reducido tamaño de la muestra, específicamente en el análisis de subgrupos. Sin embargo, los resultados indican que los pacientes bipolares manifiestan una estructura de la personalidad diferente que los individuos sanos y quela comorbilidad psiquiátrica en este trastorno se asocia con rasgos específicos de personalidad. Estos hallazgos indican que la personalidad, al menos hasta cierto punto, media el fenómeno de la comorbilidad en el trastorno bipolar (AU)

Temperament and character traits may determine differences in clinical presentations and outcome of bipolar disorder. We compared personality traits in bipolar patients and healthy individuals using the Temperament and Character Inventory (TCI) and sought to verify whether comorbidity with alcoholism or anxiety disorders is associated with specific personality traits. Seventy-three DSM-IV bipolar patients were compared to 63 healthy individuals using the TCI. In a second step, the bipolar sample was subgrouped according to the presence of psychiatric comorbidity (alcoholism, n = 10; anxiety disorders; n = 23; alcoholism plus anxiety disorders, n = 21; no comorbidity, n = 19). Bipolar patients scored statistically higher than the healthy individuals on novelty seeking, harm avoidance and self-transcendence and lower on self-directedness and cooperativeness. Bipolar patients with only comorbid alcoholism scored statistically lower than bipolar patients without any comorbidity on persistence. Bipolar patients with only comorbid anxiety disorders scored statistically higher on harm avoidance and lower on self-directedness than bipolar patients without any comorbidity. Limitations of this study include the cross-sectional design and the small sample size, specifically in the analysis of the subgroups. However, our results suggest that bipolar patients exhibit a different personality structure than healthy individuals and that presence of psychiatric comorbidity in bipolar disorder is associated with specific personality traits. These findings suggest that personality, at least to some extent, mediates the comorbidity phenomena in bipolar disorder (AU)

Novelty seeking as a moderator of familial risk for alcohol dependence.

BACKGROUND: Disinhibitory personality traits such as high novelty seeking (NS) are moderately heritable, and individuals with substance use disorders (SUDs) frequently exhibit such traits. However, recent studies have cast doubt on the supposition that such traits are true familial risk factors for SUD and particularly for alcohol dependence. Another possibility is that familial risk interacts with personality-associated risk, in which case the association between personality and familial risk might depend on sample composition, accounting for the lack of consensus among studies to date. We examined this possibility by analyzing the association between NS and alcohol dependence in individuals at intermediate and high levels of familial risk for alcohol dependence. METHODS: Data from the Collaborative Study on the Genetics of Alcoholism, a multisite family study, were examined. Subjects were 1,111 adult siblings of alcohol-dependent index cases. Parental diagnoses of alcohol dependence and personality scores of NS from the Tridimensional Personality Questionnaire were used to predict alcohol dependence. RESULTS: A significant interaction between NS and familial risk for alcoholism was seen, such that NS was a significantly stronger predictor of alcohol dependence in subjects with one or more parents with alcohol dependence than in subjects without alcohol-dependent parents. CONCLUSIONS: Novelty seeking and familial risk interact so that the risk associated with high NS is magnified in families with parental alcohol dependence and NS is a moderator of familial risk. Accordingly, high NS is strongly associated with alcohol dependence in subjects with a parent diagnosed with alcohol dependence, but low NS may protect against the risk associated with familial alcoholism. This interaction may account for conflicting findings from studies that have examined this question previously.

A dopamine transporter polymorphism is a risk factor for borderline personality disorder in depressed patients.

BACKGROUND: Borderline personality disorder (BPD) is often co-morbid with major depression and may complicate its treatment. We were interested in differences in genetic and developmental risk factors between depressed patients with or without a co-morbid BPD. METHOD: Out-patients with major depressive disorder were recruited for two treatment trials. Assessment of depressed patients included the assessment of personality disorders, developmental risk factors and DNA samples for genetic analyses. RESULTS: In each study there was a significant association between the 9-repeat allele of the dopamine transporter (DAT1) and BPD, with odds ratios (OR) > 3 and p < or = 0.02. This association remained significant when developmental risk factors for BPD (childhood abuse and neglect and borderline temperament) were also included in the analyses. The OR was even larger in the depressed patients aged > or = 35 years (OR 9.31, p = 0.005). CONCLUSION: This replicated association in depressed patients between the 9-repeat allele of DAT1 and BPD may provide clues to understanding the neurobiology of BPD. The finding that the association is larger in the older depressed patients, suggests that the 9-repeat allele may be associated with a poorer prognosis BPD, rather than a young adult limited variant of BPD.

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.