The Taq IA polymorphism linked to the DRD2 gene is related to lower attention and less inhibitory control in alcoholic patients

The TaqIA polymorphism linked to the DRD2 gene has been associated with alcoholism. The aim of this work is to study attention and inhibitory control as per the continuous performance test and the stop task in a sample of 50 Spanish male alcoholic patients split into two groups according to the presence of the TaqIA1 allele in their genotype. Our results show that alcoholics carrying the TaqIA1 allele present lower sustained attention and less inhibitory control than those patients without such allele.

The ANKK1 protein associated with addictions has nuclear and cytoplasmic localization and shows a differential response of Ala239Thr to apomorphine

The TaqIA single-nucleotide polymorphism (SNP), which is the most widely studied genetic polymorphism in addictions, is located at the gene that encodes the RIP kinase ANKK1 near the gene for dopamine receptor D2. The TaqIA SNP is in strong linkage disequilibrium with the SNP rs7118900, which changes the alanine at position 239 to threonine in the ANKK1 protein (Ala239/A2; Thr239/A1). In silico analysis has predicted that this polymorphic substitution creates an additional phosphorylation site in the kinase domain of ANKK1. To investigate the contribution of ANKK1 to the pathophysiology of TaqIA-associated phenotypes, we analyzed transfected HEK293T cells with the human ANKK1-kinase(Ala239) and ANKK1-kinase(Thr239) variants tagged with GFP. We observed that the ANKK1-kinase is located in both the nucleus and the cytoplasm, suggesting that there is nucleocytoplasmic shuttling of this putative signal transducer. In addition, we found that the Ala239Thr ANKK1-kinase polymorphism exhibited strong expression differences in both the nucleus and the cytoplasm at basal level and when stimulated with the dopamine agonist apomorphine. Specifically, the ANKK1-kinase(Thr239) variant showed the highest level of basal protein expression, while ANKK1-kinase(Ala239) was 0.64-fold lower. After treatment with apomorphine, ANKK1-kinase(Ala239) showed a 2.4-fold increment in protein levels, whereas a 0.67-fold reduction was observed in ANKK1-kinase(Thr239). Thus, here we provide the first evidence of functional ANKK1 differences that are marked by TaqIA and could be associated with vulnerability to addiction.

The D2 dopamine receptor gene variant C957T affects human fear conditioning and aversive priming

Polymorphisms of DRD2 and ANKK1 have been associated with psychiatric syndromes where there is believed to be an underlying learning process deficit such as addiction, post-traumatic stress disorder and psychopathy. We investigated the effects of the DRD2 C957T and ANKK1 TaqIA single nucleotide polymorphism (SNP), which have been associated with psychopathic traits in alcoholic patients, on fear conditioning and aversive priming in healthy volunteers. We found that the DRD2 C957T SNP, but not the ANKK1 TaqIA SNP, was associated with both differential conditioning of the skin conductance response and the aversive priming effect. There were no differences between the genotype groups with respect to the extinction of the skin-conductance conditioned response. These results suggest that the C957T SNP could be related to learning differences associated with the risk of developing psychiatric disorders in individuals that are carriers of the C homozygous genotype. Our genetic data raise the possibility that the dopaminergic system functional variations determined by this SNP could affect fear learning.

Bipolar disorder associated to substance use disorders (dual diagnosis). Systematic review of the scientific evidence and expert consensus

The present work focuses on the so-called dual diagnosis (DD): bipolar disorder (BD) associated with substance use disorders (SUD). Although the psychiatrists who treat patients with BD and physicians in charge of patients with SUD frequently find this association with DD, unfortunately there are few scientific works that have studied this association. The Spanish Working Group on Bipolar Disorders in Dual Diagnosis reviewed the published material using a Medline search and selected the most relevant articles. Following this, the Work Group developed an expert consensus in DD and finally, a survey was performed among a group of experts in this disorder to cover the areas that were not fully addressed by the scientific evidence or in those areas in which the Work Group was unable to reach a consensus. We conclude that, in view of the above, establishment of a consensus is a valid tool to complement the current scientific evidence.

DRD2 and ANKK1 genotype in alcohol-dependent patients with psychopathic traits: association and interaction study

BACKGROUND

The TaqI-A polymorphism of the ANKK1 gene, adjacent to the DRD2 gene, has been associated with alcoholism and other psychiatric conditions, although other DRD2 gene variants, such as the C957T polymorphism, could be related to these phenotypic traits.

AIMS

To investigate the contribution of the TaqI-A and the C957T polymorphisms to the presence of psychopathic traits in patients with alcoholism.

METHOD

We performed association and interaction analyses of the polymorphisms in 150 controls and 176 male alcohol-dependent patients assessed for the presence of dissocial personal disorder, using the Psychopathy Checklist-Revised (PCL-R).

RESULTS

There was a significant association of the TaqI-A and C957T polymorphisms when both genotypes were present, with PCL-R scores of F(1-171=0.13) (P=0.01) and a frequency of dissocial personal disorder OR=10.52, P<0.001.

CONCLUSIONS

The TaqI-A of the ANKK1 gene and the C957T of the DRD2 gene are epistatically associated with psychopathic traits in alcohol-dependent patients.

Selective serotonin reuptake inhibitors: use in children and adolescents with major depressive disorder

Treatment od depression in children and adolescents is a health care question of primary importance and it is presently associated to significant social concern. In recent years some studies have appeared that throw light on the question of the use of antidepressants in these sectors of the population in which they have been used. Information provided by national agencies, associations of health professional's guidelines and other publications have been reviewed. The results show an increase in aggressive and disinhibitional behavior, irritability, self-injuries and an increase in suicidal motivation with the use of antidepressants in children and adolescents. It can be added that no completed suicides have been recorded. Proof of antidepressant effectiveness only appears in the case of fluoxetine for moderate to severe depressions in children and adolescents and for tricyclic antidepressants in adolescents. The important methodological difficulties and the lack of studies only allow to consider the results as exploratory and it is hard to obtain definitive clinical results, however, they are useful to guide future investigation.

[Executive dysfunctions in adults with attention deficit hyperactivity disorder]

INTRODUCTION

Several different follow-up studies have shown that attention deficit hyperactivity disorder (ADHD) can persist into adulthood.

AIM

To review the findings in adults with ADHD related to alterations in the executive functions.

DEVELOPMENT

Research conducted among children with ADHD has revealed the existence of alterations in different tasks that evaluate the executive functions, such as the planning test, sustained attention tasks, cognitive flexibility, verbal fluency and working memory tasks, as well as several inhibition response tasks. In adults with ADHD, despite the lower number of reports in the literature and the methodological shortcomings that exist in some studies, analogous results have also been described with respect to executive functioning, namely, disorders affecting inhibition response, the capacity for planning, difficulties in cognitive flexibility and verbal fluency, and problems with working memory, which include aspects of spatial working memory, logical or visual memory.

CONCLUSIONS

The findings we have available at present enable us to confirm the persistence of executive dysfunctions in adult patients with ADHD that are similar to those observed in children with ADHD.

C957T DRD2 polymorphism is associated with schizophrenia in Spanish patients

OBJECTIVE

The objective was to confirm whether a homozygous genotype for the C957 allele of the C957T DRD2 gene single nucleotide polymorphism (SNP) is associated with schizophrenia in an independent study population.

METHOD

We examined the genotypic distribution of this SNP in a set of clinically ascertained schizophrenic patients (n = 131) and age-matched control subjects (n = 364). Individuals were genotyped using automated analysis of fluorescently labeled PCR products.

RESULTS

The distribution of grouped genotypes for the C957T DRD2 SNP (CC vs. CT, TT) showed that C homozygote genotype was over-represented in our patient sample when compared with control subjects. This difference reaches the statistical significance (chi(2) = 7.0; df = 1; P = 0.008; OR = 2.05; % CI 1.2-3.4).

CONCLUSION

The findings of this study provide additional evidence that genetic variation at the DRD2 gene plays an important role in the vulnerability to schizophrenia.

[Oxcarbazepine in the prevention of epileptic syndromes in alcohol detoxification]

INTRODUCTION

Alcohol withdrawal syndrome may be accompanied by severe complications, such as epileptic syndromes or delirium tremens. A number of pharmacological strategies, especially benzodiazepines (BZD), have been used in their treatment and prevention, although problems can arise from the use of these drugs due to their addictive properties. The classical anticonvulsive drugs are rarely employed as an alternative because of their side effects, but the latest generation of substances could be especially useful. AIMS. The aim of this study was to examine the safety of oxcarbazepine (OXC) in the prevention of epileptic seizures and complications deriving from the withdrawal syndrome in alcohol detoxification treatment.

PATIENTS AND METHODS

The study involved a comparison of two groups of patients with a syndrome of physical dependence on alcohol, 42 of whom were treated with OXC and the remaining 42 received BZD as part of a programmed detoxification therapy.

RESULTS

Both OXC and BZD were equally efficient in preventing the appearance of epileptic complications and in reducing withdrawal symptoms. Overall, OXC produced fewer adverse events (p < 0.001) and offered fewer problems when it came to ending administration (p < 0.001).

CONCLUSIONS

OXC can be a valuable alternative to BZD and other pharmacological treatments in the prevention of complications in detoxification therapy, especially because of the absence of addictive properties and its having a better safety profile than classical anticonvulsant drugs.

CLINICAL PREDICTORS OF RESPONSE TO NALTREXONE IN ALCOHOLIC PATIENTS: WHO BENEFITS MOST FROM TREATMENT WITH NALTREXONE?

AIMS

To determine the clinically ascertained variables that are related to satisfactory response to naltrexone (NTX) treatment of alcohol dependence after detoxification.

METHODS

The use of intake and outcome variables were measured in a randomized 3-month open-controlled trial comparing the effects of naltrexone plus psychotherapy treatment versus psychotherapy treatment alone on the maintenance of abstinence in the final 28 days (n = 336, all male).

RESULTS

Predictors of a positive response to NTX treatment were family history of alcoholism (P = 0.010), early age at onset of drinking problems (P = 0.014) and comorbid use of other drugs of abuse (P < 0.001). Among the subjects not treated with NTX, the greater the number of predictor variables, the lower the final 28 days abstinence rates (P = 0.00003), but this was not the case in patients treated with NTX (P = 0.844).

CONCLUSIONS

Patients with these features, suggesting biological vulnerability overall have poorer outcomes, but this can be reduced with NTX treatment. The type of alcoholism should be considered before deciding on the pharmacological strategy.

[Efficacy of naltrexone in the treatment of alcohol dependence disorder in women]

Alcoholism is a major public health problem. Although its prevalence is higher in men, the clinical and social repercussions of alcoholism in women are also of great concern, as they have differential characteristics in different vulnerability, and thus therapeutic implications. In recent years, we have seen an increase of the percentages of women with problems related to alcohol consumption in Spain. Several pharmacological treatments as the antagonist of the opioid receptors naltrexone have demonstrated efficacy in the treatment of dehabituation of alcoholism in males, however, there are no studies in the female population. This report is the first randomized study about the efficacy of naltrexone in the treatment of dehabituation in women with alcohol dependence disorder.

METHODS

In a 12 week, single-blind, randomized trial, we studied 100 women with alcohol dependence disorder (DSM-IV), evaluating the efficacy of adding naltrexone as adjunctive treatment to the dehabituation treatment.

RESULTS

The naltrexone group showed a lower rate of alcohol relapse during the follow-up period (76 % vs. 46%; chi2=8.239; p=0.004), and significantly lower dropout rates (16% vs. 38 %; chi2=5.074; p=0.024). We also found a lower number of days of intoxication (2.88 vs. 14.64; t=2.732; p=0.011).

CONCLUSIONS

Naltrexone shows efficacy as adjunctive treatment to maintain abstinence in women with alcohol dependence disorder. Further studies are needed to confirm the efficacy of this treatment and to find specific predictors of good outcome in women.

Effects of topiramate in the treatment of alcohol dependence

BACKGROUND

Anticonvulsant drugs have been used in the treatment of alcohol addiction with relatively good results. The purpose of the present study was to evaluate tolerance and safety of topiramate in patients presenting alcohol dependence.

METHODS

We studied 24 patients that fulfilled alcohol-dependence criteria (DSM-IV) and presented other psychiatric disorders for which the use of topiramate was indicated. During the 12 weeks of the study, the patients received topiramate (262 mg/day) plus the psychoactive drugs they were taking for the other disorders. Carbohydrate-deficient transferrin (CDT) values and measures of craving and alcohol use were taken every 2 weeks.

RESULTS

Baseline rating of amount and frequency of craving and alcohol use decreased significantly by week 2, and CDT values decreased from week 6. Topiramate was well tolerated, and there were only three dropouts due to adverse events.

CONCLUSION

Topiramate is safe and well tolerated, and may be beneficial in the treatment of alcohol dependence. A placebo-controlled study would be of interest.

IDRD2 TaqIA polymorphism is associated with urinary homovanillic acid levels in a sample of Spanish male alcoholic patients

The TaqIA1 allele of the dopamine receptor gene D2 (DRD2) has been associated with alcoholism, as well as with other addictive behaviours. The exact nature of how the presence of this allele can be a vulnerability factor in the development of alcoholism remains unclear. In this study we found that the presence in the DRD2 genotype of the TaqIA1 allele in Spanish alcoholics is associated with higher levels of urine homovanillic acid (HVA) when compared to patients homozygous for the TaqIA2 allele. A sample of 142 Spanish male alcoholic patients was split into 2 groups on the basis of the presence or absence of the A1 allele in their genotype. The urine sample was analyzed by high performance liquid cromatography (HPLC), and the concentration of homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5-HIAA) and vanilylmandelic acid (VMA) was determined. We found a statistical difference in the concentration of HVA between the groups, that suggests this polymorphism could be related to the variance of urine HVA levels.

Naltrexone versus acamprosate: one year follow-up of alcohol dependence treatment

Naltrexone and acamprosate reduce relapse in alcohol dependence. They have not yet been compared in a published trial. The aim of this study was to compare the efficacy of these compounds in conditions similar to those in routine clinical practice. Random allocation to a year of treatment with naltrexone (50 mg/day) or acamprosate (1665-1998 mg/day) was made in 157 recently detoxified alcohol-dependent men with moderate dependence (evaluated using the Addictions Severity Index and Severity of Alcohol Dependence Scale). All were patients whom a member of the family would accompany regularly to appointments. Alcohol consumption, craving and adverse events were recorded weekly for the first 3 months, and then bi-weekly, by the treating psychiatrist who was not blinded. At 3-monthly intervals, investigators who were blinded to the treatment documented patients' alcohol consumption based on patients' accounts, information given by the psychiatrists when necessary, and reports from patients' families. Serum gamma-glutamyltransferase (GGT) was also measured. Efforts were made to sustain the blindness of the investigators. The same investigator did not assess the same patient twice. The integrity of the blindness was not checked. There was no difference between treatments in mean time to first drink (naltrexone 44 days, acamprosate 39 days) but the time to first relapse (five or more drinks in a day) was 63 days (naltrexone) versus 42 days (acamprosate) (P = 0.02). At the end of 1 year, 41% receiving naltrexone and 17% receiving acamprosate had not relapsed (P = 0.0009). The cumulative number of days of abstinence was significantly greater, and the number of drinks consumed at one time and severity of craving were significantly less, in the naltrexone group compared to the acamprosate group, as was the percentage of heavy drinking days (P = 0.038). More patients in the acamprosate than the naltrexone group were commenced on disulfiram during the study. Naltrexone patients attended significantly more group therapy sessions, though this could not explain their better outcome. There were non-significant trends for the naltrexone group to comply better with medication, to stay in the study longer, and to show greater improvement over baseline in serum GGT.