Naltrexone alone and with sertraline for the treatment of alcohol dependence in Alaska natives and non-natives residing in rural settings: a randomized controlled trial.

BACKGROUND: Access to specialty alcoholism treatment in rural environments is limited and new treatment approaches are needed. The objective was to evaluate the efficacy of naltrexone alone and in combination with sertraline among Alaska Natives and other Alaskans living in rural settings. An exploratory aim examined whether the Asn40Asp polymorphism of the mu-opioid receptor gene (OPRM1) predicted response to naltrexone, as had been reported in Caucasians. METHODS: Randomized, controlled trial enrolling 101 Alaskans with alcohol dependence, including 68 American Indians/Alaska Natives. Participants received 16 weeks of either (1) placebo (placebo naltrexone + placebo sertraline), (2) naltrexone monotherapy (50 mg naltrexone + sertraline placebo) and (3) naltrexone + sertraline (100 mg) plus nine sessions of medical management and supportive advice. Primary outcomes included Time to First Heavy Drinking Day and Total Abstinence. RESULTS: Naltrexone monotherapy demonstrated significantly higher total abstinence (35%) compared with placebo (12%, p = 0027) and longer, but not statistically different, Time to First Heavy Drinking Day (p = 0.093). On secondary measures, naltrexone compared with placebo demonstrated significant improvements in percent days abstinent (p = 0.024) and drinking-related consequences (p = 0.02). Combined sertraline and naltrexone did not differ from naltrexone alone. The pattern of findings was generally similar for the American Indian/Alaska Native subsample. Naltrexone treatment response was significant within the group of 75 individuals who were homozygous for OPRM1 Asn40 allele. There was a small number of Asp40 carriers, precluding statistical testing of the effect of this allele on response. CONCLUSIONS: Naltrexone can be used effectively to treat alcoholism in remote and rural communities, with evidence of benefit for American Indians and Alaska Natives. New models of care incorporating pharmacotherapy could reduce important health disparities related to alcoholism.

Schizophrenia and psychotic symptoms in families of two American Indian tribes.

BACKGROUND: The risk of schizophrenia is thought to be higher in population isolates that have recently been exposed to major and accelerated cultural change, accompanied by ensuing socio-environmental stressors/triggers, than in dominant, mainstream societies. We investigated the prevalence and phenomenology of schizophrenia in 329 females and 253 males of a Southwestern American Indian tribe, and in 194 females and 137 males of a Plains American Indian tribe. These tribal groups were evaluated as part of a broader program of gene-environment investigations of alcoholism and other psychiatric disorders. METHODS: Semi-structured psychiatric interviews were conducted to allow diagnoses utilizing standardized psychiatric diagnostic criteria, and to limit cultural biases. Study participants were recruited from the community on the basis of membership in pedigrees, and not by convenience. After independent raters evaluated the interviews blindly, DSM-III-R diagnoses were assigned by a consensus of experts well-versed in the local cultures. RESULTS: Five of the 582 Southwestern American Indian respondents (prevalence = 8.6 per 1000), and one of the 331 interviewed Plains American Indians (prevalence = 3.02 per 1000) had a lifetime diagnosis of schizophrenia. The lifetime prevalence rates of schizophrenia within these two distinct American Indian tribal groups is consistent with lifetime expectancy rates reported for the general United States population and most isolate and homogeneous populations for which prevalence rates of schizophrenia are available. While we were unable to factor in the potential modifying effect that mortality rates of schizophrenia-suffering tribal members may have had on the overall tribal rates, the incidence of schizophrenia among the living was well within the normative range. CONCLUSION: The occurrence of schizophrenia among members of these two tribal population groups is consistent with prevalence rates reported for population isolates and in the general population. Vulnerabilities to early onset alcohol and drug use disorders do not lend convincing support to a diathesis-stressor model with these stressors, commonly reported with these tribes. Nearly one-fifth of the respondents reported experiencing psychotic-like symptoms, reaffirming the need to examine sociocultural factors actively before making positive diagnoses of psychosis or schizophrenia.

Linkage disequilibrium and association analysis of alpha-synuclein and alcohol and drug dependence in two American Indian populations.

BACKGROUND: Alpha-synuclein is involved in dopaminergic neurotransmission and has been implicated in a number of neurodegenerative disorders, such as Parkinson's disease. Recent studies, in humans and in rat and monkey models, have suggested that alpha-synuclein may play a role in the development and maintenance of certain addictive disorders. METHODS: Fifteen single-nucleotide polymorphisms (SNPs) in the alpha-synuclein gene (SNCA) and 1 upstream microsatellite repeat (NACP-REP1) were assayed in Southwest (SW; n=514) and Plains (n=420) American Indian populations. Patterns of linkage disequilibrium (LD) at SNCA were determined for the 2 populations and compared with Caucasian, African, and Asian populations in the HapMap database (http://www.hapmap.org). Assayed alleles and constructed haplotypes in the study populations were tested for association with 4 clinical phenotypes [alcohol dependence, alcohol use disorders, drug dependence, and drug use disorders (lifetime diagnoses)] as well as with 2 symptom count phenotypes (all 18 questions and the 8 questions diagnostic for alcohol dependence). RESULTS: Patterns of LD at SNCA were similar in both Indian populations and were consistent with the LD structure in other populations as reflected in the HapMap database. Single allele tests revealed significant associations between 4 SNPs and drug dependence in the SW population and between 2 of those SNPs plus 2 other SNPs and drug dependence in SW males only. In the Plains population, a significant association was detected only in males between 2 SNPs and alcohol use disorders and between 1 SNP and alcohol dependence. In the SW population, 1 SNP was marginally significant with the total symptom count. However, in all cases, the support was modest and disappeared with correction for multiple comparisons. No association was found between constructed haplotypes and any of the phenotypes in either population. CONCLUSIONS: Despite modest support for association between multiple SNCA SNPs and several of the addictive disorders tested in this study, statistical significance disappeared after correction for multiple testing. Thus, our data do not support a role for a variant in the SNCA gene that contributes to alcohol or drug addiction in the 2 studied American Indian populations. Future research may focus on variants in the promoter region that could cause the changes in mRNA and protein levels observed in previous studies.

Validity of the SMAST in two American Indian tribal populations.

The standardized evaluation of alcoholism and other psychopathologies in minority populations, particularly American Indians, has long been questioned. This study investigated the validity of one of the most commonly applied assessments for alcoholism--the Short Michigan Alcohol Screening Test (SMAST)--in two distinct American Indian tribal groups. We analyzed data collected from 1989 to 1995 from largely community representative samples of 456 Southwestern and 214 Plains Indians ages 21 or older. For comparison, alcohol dependence was diagnosed using Diagnostic and Statistical Manual of Mental Disorders, Third Edition-Revised (DSM-III-R) criteria from a detailed, modified version of the Schedule for Affective Disorders and Schizophrenia--Lifetime (SADS-L). Accuracy of the SMAST was quantified as sensitivity, specificity, likelihood ratios, and the area under the curve for receiver operating characteristics, using the DSM-III-R diagnosis as the reference. The standard SMAST cutoff score of > or = 3 had a demonstrated sensitivity 86% to 95%, but did not perform well in terms of specificity (23%-47%). Significantly higher cutoff scores (> or = 5 for both genders in the Southwestern tribe and 8 and > or = 6 for men and women in the Plains tribe) were required to demonstrate acceptable levels of specificity in both tribes. The findings suggest that the SMAST is not a valid tool to screen for alcohol misuse in these two tribal populations. The highly elevated and different thresholds required from one population to the next and from one gender to the next constitute a significant obstacle to the use of the instrument.

Use of the MMPI-2 in American Indians: I. Comparability of the MMPI-2 between two tribes and with the MMPI-2 normative group.

The comparability of the MMPI-2 in American Indians with the MMPI-2 normative group was investigated in a sample of 535 Southwestern and 297 Plains American Indian tribal members with contrasting sociocultural and historical origins. Both American Indian tribal groups had clinically significant higher T scores (> 5 T points) on 5 validity and clinical scales, 6 content scales, and 2 supplementary scales than did the MMPI-2 normative group. There were no significant differences between the 2 tribal groups on any of the MMPI-2 clinical, content, or supplementary scales. Matching members of both tribes with persons in the MMPI-2 normative group on the basis of age, gender, and education reduced the magnitude of the differences between the 2 groups on all of these scales, although the differences in T scores still exceeded 5 T points. It appears likely that the MMPI-2 differences of these 2 American Indian groups from the normative group may reflect their adverse historical, social, and economic conditions.

Use of the MMPI-2 in American Indians: II. Empirical correlates.

R. W. Robin, R. L. Greene, B. Albaugh, A. Caldwell, and D. Goldman (2003) reported that members of 2 American Indian tribal groups had statistically significant higher T scores on several MMPI-2 clinical, content, and supplementary scales than did the MMPI-2 normative group. The present study investigated the empirical correlates of the MMPI-2 scales in these American Indian tribal members. There were a large number of significant correlates reflecting antisocial symptoms with Scales 4 (Psychopathic Deviate), 9 (Hypomania), Anger, and Antisocial Practices. There were even a larger number of significant correlates reflecting generalized distress and negative affect with Scales 7 (Psychosthenia), 8 (Schizophrenia), Anxiety, Obsessions, Depression, and Welsh Anxiety. The rationally derived MMPI-2 content scales generally had larger correlations with these constructs than the clinical scales. Thus, the differences reported by R. W. Robin et al. (2003), appear to reflect behaviors and symptoms that American Indians participants were experiencing rather than test bias.

Allelic variation at alcohol metabolism genes ( ADH1B, ADH1C, ALDH2) and alcohol dependence in an American Indian population.

Enzymes encoded by two gene families, alcohol dehydrogenase ( ADH) and aldehyde dehydrogenase ( ALDH), mediate alcohol metabolism in humans. Allelic variants have been identified that alter metabolic rates and influence risk for alcoholism. Specifically, ADH1B*47His (previously ADH2-2) and ALDH2-2 have been shown to confer protection against alcoholism, presumably through accumulation of acetaldehyde in the blood and a resultant 'flushing response' to alcohol consumption. In the current study, variants at ADH1B (previously ADH2), ADH1C (previously ADH3), and ALDH2 were assayed in DNA extracts from participants belonging to a Southwest American Indian tribe ( n=490) with a high prevalence of alcoholism. Each subject underwent a clinical interview for diagnosis of alcohol dependence, as well as evaluation of intermediate phenotypes such as binge drinking and flushing response to alcohol consumption. Detailed haplotypes were constructed and tested against alcohol dependence and related intermediate phenotypes using both association and linkage analysis. ADH and ALDH variants were also assayed in three Asian and one African population (no clinical data) in order to provide an evolutionary context for the haplotype data. Both linkage and association analysis identified several ADH1C alleles and a neighboring microsatellite marker that affected risk of alcohol dependence and were also related to binge drinking. These data strengthen the support for ADH as a candidate locus for alcohol dependence and suggest further productive study.