Jobst Boening

Alcohol dependence, family history, and D2 dopamine receptor function as neuroendocrinologically assessed with apomorphine

Fifteen alcohol dependent men with an alcohol dependent first degree relative (i.e. family history positive or FHP), 15 well matched alcohol dependent men without a family history for alcohol dependence (i.e. family history negative or FHN), and 15 healthy controls (CONTR) participated in this study. The three groups were compared according to their postsynaptic D2 dopamine receptor function as assessed by growth hormone release after stimulation with the dopamine receptor agonist apomorphine. Statistical evaluation was done by planned comparisons within a one-way ANOVA. Alcohol dependent subjects significantly differed from CONTRs as long as family history was not taken into account (t(42) = 2.38; P = 0.022*). When differentiating according to family history, both FHPs and FHNs maintained a blunted growth hormone response. However, the difference between FHNs and CONTRs, though present, dropped out of statistical significance (t(42) = 1.65; P = 0.105); at the same time, the difference between FHPs and CONTRs became slightly stronger (t(42) = 2.47; p = 0.017*). In conclusion, our data give neuroendocrinological support to the assumption that a reduced D2 dopamine receptor function in alcohol dependent men is not only a state marker of residual heavy drinking but also a genetically determined trait marker.

Cortisol concentrations, stress-coping styles after withdrawal and long-term abstinence in alcohol dependence.

Alcohol‐dependent patients face a substantial risk of relapse after detoxification. A major risk factor for relapse is stress which is reflected biologically by various physiological changes that include an activation of the hypothalamic‐pituitary‐adrenal (HPA) axis and release of glucocorticoids. The prospective study examined cortisol concentrations and stress‐coping styles in relation to abstinence 1 year following discharge from treatment. Cortisol concentrations were measured in the plasma of 46 alcohol‐dependent patients (12 women) on initial presentation for treatment (day 1), and again in plasma and in cerebrospinal fluid (CSF) after 6 weeks of abstinence (day 40). These results were compared with those of 26 age‐ and sex‐matched, healthy control subjects. After withdrawal, the patients completed a comprehensive baseline assessment including a stress‐coping questionnaire (Stressverarbeitungsfragebogen SVF120) and were monitored for 1 year after discharge. Negative stress‐coping styles (e.g. flight, resignation) positively correlated with higher cortisol concentration in plasma and in CSF after withdrawal (day 40). Compared with relapsers after 1 year, abstainers had significantly lower levels for cortisol in CSF, whereas the stress‐coping styles did not differ between abstainers and relapsers in this sample. These findings suggest that relatively stable personality traits like stress‐coping styles have no measurable influence on abstinence. The lower cortisol concentration in CSF as an indicator for HPA axis functioning is associated with long‐term abstinence in detoxified alcoholics.

Social Factors but Not Stress-Coping Styles Predict Relapse in Detoxified Alcoholics

Alcohol-dependent patients face a substantial risk of relapse after detoxification. Though psychosocial stress and coping strategies are regarded as major contributing factors in returning to drinking, the direct effects of coping styles on relapse are not clear. In this treatment outcome study, a mixed gender sample of 130 detoxified and well-characterized alcohol-dependent patients (37 women) was followed up over a period of 12 months after 6 weeks of inpatient treatment. Patients had completed a comprehensive baseline assessment, including a stress coping questionnaire (SVF120). We hypothesized that these individual stress coping styles would contribute to treatment outcome. A logistic regression analysis was used to evaluate the impact of stress coping styles, as well as the effect of pretreatment drinking and social characteristics on relapse. Approximately half the patients (49%) relapsed within 1 year after treatment. In contrast to our hypothesis, stress coping styles did not predict relapse. However, significant predictors of relapse were social factors related to living situation (living alone), marital status (being separated from the spouse) and pretreatment frequency of alcohol intake. These findings suggest that a partnership is more relevant for the risk of relapse than stress coping styles.

Sensation seeking, alcoholism and dopamine activity

Sensation seeking scale (SSS) scores were determined in 15 alcohol dependent men with a positive family history for alcoholism (FHP), in 15 alcohol dependent men with a negative family history for alcoholism (FHN) and in 15 well-matched healthy male controls (CONTR). Both FHPs and FHNs suffered from longlasting alcohol dependence meeting ICD-10 and DSM-III-R diagnostic criteria. Dopamine activity was neuroendocrinologically assessed by measuring the amount of growth hormone released after stimulation with the dopamine receptor agonist apomorphine. Planned comparisons within a one-way ANOVA yielded significantly elevated levels of boredom susceptibility (BOS) in both FHPs and FHNs against CONTRs. SSS total scores, while approaching statistical significance, were elevated in FHPs only. Partial correlations (controlling for age, body weight, alcohol intake and duration of dependence) were calculated to examine the relationship between SSS and dopamine activity. Among the SSS subtraits, BOS revealed the highest correlation in each group. However, only in CONTRs did the relationship between BOS and dopamine activity reach statistical significance.

Serotonin transporter gene polymorphism and personality traits in primary alcohol dependence

Summary We tested the hypothesis of an association between the serotonin transporter (5-HTT) gene regulatory region polymorphism and the Temperament and Character Inventory (TCI) personality dimension of Harm Avoidance. For the study, 124 subjects seeking inpatient treatment for primary alcohol dependence were grouped by their 5-HTT genotype and assessed with the TCI. Genotypes differed statistically significantly in Harm Avoidance but not in any other personality trait. This gives support to the hypothesis that the TCI temperament Harm Avoidance is associated with serotonergic neurotransmission in primary alcohol dependence.

A Functional Polymorphism in the Promoter Region of the Monoamine Oxidase A Gene Is Associated with the Cigarette Smoking Quantity in Alcohol-Dependent Heavy Smokers

Tobacco smoking represents a leading cause of morbidity and mortality with a strong dose-response relation between the amount of smoking and the risks of tobacco-related diseases and death. The quantity that is smoked is determined predominantly by genetic factors. The present study examined whether there is an association between the quantity of cigarettes smoked and length variation of a functional 30-bp repeat polymorphism in the promoter region of the monoamine oxidase A (MAO-A) gene. The number of 30-bp repeats, which is associated with enzyme activity was assessed in 121 Caucasian men suffering from both alcohol and tobacco dependence. Analysis revealed that the highly active long allele (4 repeat) is associated with a significantly greater amount of cigarette smoking in comparison with the less active short allele (3 repeat). In a logistic regression model (dichotomized), smoking quantity was significantly predicted by MAO-A genotype while no other variable (age, height, body weight, frequency of smoking, quantity and frequency of alcohol consumption) met the significance level. Since tobacco smoke is a potent inhibitor of MAO-A, this result could be regarded as a genotype-related dosage effect. Taken together, in alcohol-dependent heavily smoking men there is evidence for a MAO-A gene-associated effect on the quantity that is smoked as reflected by the daily number of cigarettes consumed.

Growth hormone response to placebo, apomorphine and growth hormone releasing hormone in abstinent alcoholics and control subjects

Abstinent alcoholics and control subjects were challenged with placebo (saline), growth hormone releasing hormone (GHRH) and apomorphine (APO). While both groups did not differ in their growth hormone response (HGH) to placebo and GHRH, the alcoholics revealed a significant lower HGH response to dopamine receptor stimulation with APO. These findings provide no evidence that in abstinent alcoholics HGH blunting after dopamine receptor stimulation could be related to an alteration at the pituitary level but they give neuroendocrinological support to the hypothesis of a lower dopamine receptor sensitivity in abstinent alcoholics.

Alcohol withdrawal and dopamine receptor sensitivtty after prolonged abstinence

1. Forty-four male inpatients suffering from moderate to severe alcohol dependence (DSM-III-R and ICD-10) as well as 14 healthy controls entered this study. Individuals were classified according to the severity of their withdrawal symptoms during detoxification i.e. group 1) no withdrawal, group 2) autonomic hyperactivity, group 3) withdrawal delirium and group 4) controls. 2. During the 6th week of treatment, that is, when all patients were recovered, controlled abstinent, and several weeks away from the end of their withdrawal syndrome, dopamine receptor sensitivity was neuroendocrinologically assessed by stimulating human growth hormone (HGH) with apomorphine (APO). 3. In a repeated measures model ANOVA, the four groups differed significantly in their HGH release. However, when excluding the controls from the analysis and focusing on alcoholics only (group 1 - 3), the significant difference disappeared. Covariates such as age, weight, quantity of drinking and duration of dependence were not related to the dependent variable. 4. In conclusion, the first significant result (with controls) reflects a blunted HGH response in alcoholics. It confirms earlier reports. The second, non significant result with the alcohol dependents only, suggests that the severity of withdrawal is not reflected by the amount of HGH released. Therefore, in alcoholics, a reduced dopamine receptor function after six weeks of abstinence, as neuro-endocrinologically assessed with apomorphine, seems to be related to alcohol dependence rather than to the severity of alcohol withdrawal.

A Three-Axes Approach of Subtyping the Alcohol Dependence Syndrome

Subtyping of alcoholics according to specific characteristics has a long tradition in alcoholism research with a number of different typologies that emerged in the literature. The goal of the present study was to test a multidimensional approach of subtyping with characteristics from different axes. Therefore, male inpatients meeting ICD-10 criteria for alcohol dependence were rated on three axes by assessing their degree of sensation seeking (personality axis), age of alcoholism onset (clinical axis) and level of dopamine activity (neurobiological axis). By using a configuration frequency analysis, we identified a subtype that was characterized by high sensation seeking early age of alcoholism onset and high dopamine activity. This subtype, which is in accordance with clinical experience and cannot be explained by antisocial personality disorder, embodied a significantly greater proportion of alcoholics than expected. The result emphasizes the usefulness of multidimensional approaches integrating personality, clinical and neurobiological characteristics.