Generalizability of the type A/type B distinction across different psychoactive substances

Applicability of Type A/B alcohol dependence in the general population

BACKGROUND

This study examined the concurrent and predictive validity of Type A/B alcohol dependence in the general population-a typology developed in clinical populations to gauge severity of dependence.

METHODS

Data were drawn from Waves 1 and 2 of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). The sample included 1,172 alcohol-dependent drinkers at baseline who were reinterviewed three years later. Latent class analysis was used to derive Type A/B classification using variables replicating the original Type A/B typology. Predictive validity of the Type A/B classification was assessed by multivariable linear and logistic regressions.

RESULTS

A two-class solution consistent with Babor's original Type A/B typology adequately fit the data. Type B alcoholics in the general population, compared to Type As, had higher alcohol severity and more co-occurring drug, mental, and physical health problems. In the absence of treatment services utilization, Type B drinkers had two times the odds of being alcohol dependent three years later. Among those who utilized alcohol treatment services, Type B membership was predictive of heavy drinking and drug dependence, but not alcohol dependence, three years later.

CONCLUSIONS

Findings suggest that Type A/B classification is both generalizable to, and valid within, the US general population of alcohol dependent drinkers. Results highlight the value of treatment for mitigating the persistence of dependence among Type B alcoholics in the general population. Screening for markers of vulnerability to Type B dependence could be of clinical value for health care providers to determine appropriate intervention.

New approaches for examining associations with latent categorical variables: applications to substance abuse and aggression

Assessments of substance use behaviors often include categorical variables that are frequently related to other measures using logistic regression or chi-square analysis. When the categorical variable is latent (e.g., extracted from a latent class analysis [LCA]), classification of observations is often used to create an observed nominal variable from the latent one for use in a subsequent analysis. However, recent simulation studies have found that this classical 3-step analysis championed by the pioneers of LCA produces underestimates of the associations of latent classes with other variables. Two preferable but underused alternatives for examining such linkages-each of which is most appropriate under certain conditions-are (a) 3-step analysis, which corrects the underestimation bias of the classical approach, and (b) 1-step analysis. The purpose of this article is to dissuade researchers from conducting classical 3-step analysis and to promote the use of the 2 newer approaches that are described and compared. In addition, the applications of these newer models-for use when the independent, the dependent, or both categorical variables are latent-are illustrated through substantive analyses relating classes of substance abusers to classes of intimate partner aggressors.

A Regression Framework for Effect Size Assessments in Longitudinal Modeling of Group Differences

The use of growth modeling analysis (GMA)--particularly multilevel analysis and latent growth modeling--to test the significance of intervention effects has increased exponentially in prevention science, clinical psychology, and psychiatry over the past 15 years. Model-based effect sizes for differences in means between two independent groups in GMA can be expressed in the same metric (Cohen's d) commonly used in classical analysis and meta-analysis. This article first reviews conceptual issues regarding calculation of d for findings from GMA and then introduces an integrative framework for effect size assessments that subsumes GMA. The new approach uses the structure of the linear regression model, from which effect sizes for findings from diverse cross-sectional and longitudinal analyses can be calculated with familiar statistics, such as the regression coefficient, the standard deviation of the dependent measure, and study duration.

Heritability and a genome-wide linkage analysis of a Type II/B cluster construct for cannabis dependence in an American Indian community

Subtyping of substance dependence disorders holds promise for a number of important research areas including phenotyping for genetic studies, characterizing clinical course, and matching treatment and prevention strategies. This study sought to investigate whether a dichotomous construct similar to Babor's Types A/B and Cloninger's Types I/II for alcohol dependence can be identified for cannabis dependence in a Native American sample. In addition, heritability of this construct and its behavior in a genetic linkage analyses were evaluated. Information on cannabis use and dependence symptoms and other psychiatric disorders was obtained using the Semi-Structured Assessment for the Genetics of Alcoholism from a community sample of 606 American Indians. Hierarchical average linkage and K means cluster analysis was used, and a three-cluster solution was found to generate the best separation of variables. Ninety-one per cent of cannabis-dependent participants fell into one of the two subtypes: Type A/I cluster (n = 114, 56%) and Type B/II cluster (n = 70, 35%). Heritability (estimated using Sequential Oligogenic Linkage Analysis Routines) was only significant for the Type B/II cluster (h(2) = 0.44, SE = 0.18, P < 0.01). Evidence for linkage was found for the Type B/II cluster (versus no diagnosis) on chromosome 16 [at 139 centimorgans (cM), Log of the Odds (LOD) score = 4.4], and on chromosome 19 (at 74 cM, LOD score = 6.4). Regions of interest for this phenotype (LOD > 1.5) were also located on chromosomes 14, 21, 22. These findings suggest that a Type B/II cannabis dependence phenotype can be identified in this population and that it is in part heritable and linked to areas of the genome identified previously for drug dependence phenotypes in this population as well as in other studies.

Ordered subsets linkage analysis of antisocial behavior in substance use disorder among participants in the Collaborative Study on the Genetics of Alcoholism

Heterogeneity in complex diseases such as Substance Use Disorder (SUD) reduces the power to detect linkage and makes replication of findings in other populations unlikely. It is therefore critical to refine the phenotype and use methods that account for genetic heterogeneity between families. SUD was operationalized as diagnosis of abuse or dependence to alcohol and/or any one of five illicit substances. Whole-genome linkage analysis of 241 extended pedigree families from the Collaborative Study on the Genetics of Alcoholism was performed in Merlin using an affected sibship design. An Ordered Subsets Analysis (OSA) using FLOSS sought to increase the homogeneity of the sample by ranking families by their density of childhood and adult antisocial behaviors, producing new maximum Nonparametric Lod (NPL) scores on each chromosome for each subset of families. Prior to OSA, modest evidence for linkage was found on chromosomes 8 and 17. Although changes in NPL scores were not statistically significant, OSA revealed possible evidence of linkages on chromosome 7, near markers D7S1795 and D7S821. NPL scores >3.0 were also observed on chromosomes 2, 3, 5, 9, and 14. However, the number of families used in these latter subsets for linkage may be too small to be meaningful. Results provide some evidence for the ability of OSA to reduce genetic heterogeneity, and add further support to chromosome 7 as a possible location to search for genes related to various SUD related processes. Nonetheless, replication of these results in other samples is essential.

The validity of cocaine dependence subtypes

Cocaine dependence (CD) is a multifactorial disorder, variable in its manifestations, and heritable. We examined the concurrent validity of homogeneous subgroups of CD as phenotypes for genetic analysis. We applied data reduction methods and an empirical cluster-analytic approach to measures of cocaine use, cocaine-related effects, and cocaine treatment history in 1393 subjects, from 660 small nuclear families. Four of the six clusters that were derived yielded heritability estimates in excess of 0.3. Linkage analysis showed genome-wide significant results for two of the clusters. Here we examine the concurrent validity of the six clusters using a variety of demographic and substance-related measures. In addition to being differentiated by a variety of cocaine-related measures, the clusters differed significantly on measures that were independent of those used to generate the clusters, i.e., demographic features and prevalence rates of co-morbid substance use and psychiatric disorders. These findings support the validity of the methods used to derive homogeneous subgroups of CD subjects and the resulting CD subtypes. Independent replication of these findings would provide further validation of this approach.

Temperament characteristics, as assessed by the tridimensional personality questionnaire, moderate the response to sertraline in depressed opiate-dependent methadone patients

During a randomized, double-blind, placebo controlled study of the effects of sertraline in depressed methadone-maintained patients, 82 completed the tridimensional personality questionnaire (TPQ) to assess whether temperament dimensions can affect treatment-related changes in mood and drug use. Mood outcome significantly differed according to scores on the reward dependence scale (RD). Low RD participants displayed a significantly better mood response to sertraline than high RD participants. Participants with high harm avoidance (HA) scores were more likely to be abstinent at the end of the 12 week trial of sertraline than low HA participants. High persistence (P) participants were less likely to be abstinent at the end of the 12-week trial. These results suggest that temperament dimensions may be important for identifying substance dependent patients more likely to benefit from pharmacological interventions for comorbid depressive disorders.

The Type A-Type B classification in a community sample of problem drinkers: structural and predictive validity

OBJECTIVE

The Type A-Type B multidimensional classification model has been useful for identifying a subgroup of alcohol dependent drinkers with more severe psychosocial problems and a poor prognosis. Evidence suggests its dimensions may be useful for identifying problem drinkers in the general population at risk for developing alcohol dependence. To date, the model has not yet been investigated for this purpose. The present study investigated the Type A/Type B distinction in a community sample of problem drinkers as well as its predictive validity among problem drinkers with no history of alcohol dependence.

METHOD

Households from a geographically delimited area in the United States were designated via random digit dialing and randomly designated members were screened for eligibility. A total of 876 participants met eligibility criteria and completed a structured interview (AUDADIS) on alcohol and other health related behaviors at baseline and at 1-year follow-up. A k-means cluster analysis was performed to identify subgroups of problem drinkers.

RESULTS

A two-cluster solution adequately fit the data and identified two main subgroups of problem drinkers consistent with a Type A-Type B distinction. The group differences held among those with and without a history of alcohol dependence and the subset of Type B drinkers with no history of alcohol dependence were approximately five times (beta = 1.56, p< or =0.01) more likely to have an initial onset of dependence than Type A drinkers at 1-year follow-up. In contrast, a DSM-IV alcohol abuse diagnosis at baseline did not predict 1-year onset of dependence.

CONCLUSIONS

The Type A-Type B model is useful for identifying untreated problem drinkers at risk for developing alcohol dependence. This model may facilitate the development of more targeted prevention efforts.

Two types of classification for male opioid dependence: identification of an opioid addict with depressive features

OBJECTIVE

There are similarities between alcoholics and opioid addicts and an overlap between both diagnostic groups. We tested the hypothesis that the type I and II classification, well established in male alcoholism, could also be relevant in a population of male opioid addicts.

METHODS

A sample of 100 hospitalized adult opioid dependent men were studied with the help of an extended semi-structured clinical interview, considering four classification criteria sets devised by Cloninger et al. (1981, 1982), von Knorring et al. (1985, 1987), Buydens-Branchey et al. (1989) and Babor et al. (1992).

RESULTS

The two types of classification could be confirmed with all four criteria sets. In at least three of four analyses, 52 patients were allocated to the same larger cluster C1, and 25 patients to a smaller cluster C2. These two groups were compared with each other with the help of the stepwise discriminant analysis. Seven variables were identified which excellently discriminate between the groups: The C2 patient is younger, has a history of therapy because of depression and a history of severe suicide attempts, also abuses benzodiazepines and becomes violent while intoxicated. His father suffers from alcoholism and received treatment because of depression. The C1 patient lacks these characteristics.

CONCLUSIONS

The hypothesis was confirmed, showing that the two types of classification for male opioid addicts is feasible. A depressive type of male opioid dependent patient was identified. Early identification of patients of this type is clinically important.

The genetics of addictions: uncovering the genes

The addictions are common chronic psychiatric diseases that today are prevented and treated using relatively untargeted and only partially effective methods. The addictions are moderately to highly heritable, which is paradoxical because these disorders require use; a choice that is itself modulated by both genes and environment. The addictions are interrelated and related to other psychiatric diseases by common neurobiological pathways, including those that modulate reward, behavioural control and the anxiety or stress response. Our future understanding of addictions will be enhanced by the identification of genes that have a role in altered substance-specific vulnerabilities such as variation in drug metabolism or drug receptors and a role in shared vulnerabilities such as variation in reward or stress resiliency.

Genomewide linkage scan for cocaine dependence and related traits: significant linkages for a cocaine-related trait and cocaine-induced paranoia

Risk for cocaine dependence (CD) is genetically influenced. We recruited a sample of small nuclear families (528 full and 155 half sibpairs) with at least one subject affected with CD. The sample was classified via Bayesian clustering as 45.5% European American (EA) and 54.5% African American (AA). Assessment, via the Semi-Structured Assessment for Drug Dependence and Alcoholism, allowed for detailed evaluation of substance dependence-related traits. To define subgroups with increased genetic homogeneity, consistent with our a priori analytic plan, we used cluster analytic methods to identify six cocaine-related symptom clusters; membership was shown to be significantly heritable. We then completed a genomewide linkage scan (409 markers) for the CD diagnosis, cocaine-induced paranoia (CIP; an outcome that occurs in some cocaine users) and the clusters (three of which contained >80% of the CD subjects). We observed a "suggestive" linkage signal on chromosome 10 for the trait of CD in the full sample; and two "suggestive" linkage signals at different locations on chromosome 3, in the EA part of the sample. We observed a genomewide-significant lod score of 3.65 for the trait of CIP on chromosome 9, in the AA part of the sample only. Our strongest results were observed for the cluster membership traits, including a lod score of 4.66 for membership in the "Heavy Use, Cocaine Predominant" cluster on chromosome 12 (in EAs only) and a lod score of 3.35 for membership in the "Moderate Cocaine and Opioid Abuse" cluster on chromosome 18. These results provide a basis for the identification of specific genes contributing to risk for these traits.

Genetic susceptibility to substance dependence

Despite what is often believed, the majority of those who experiment with substances with a dependence potential do not develop dependence. However, there is a subpopulation of users that easily becomes dependent on substances, and these individuals exhibit pre-existing comorbid traits, including novelty seeking and antisocial behavior. There appears to be a genetic basis for the susceptibility to dependence and these comorbid traits. Animal studies have identified specific genes that can alter susceptibility to dependence and response to novelty. The mechanisms underlying the genetic susceptibility to dependence and response to novelty are complex, but genetic susceptibility plays a significant role in the transition from substance use to dependence and from chronic use to addiction. We discuss two models to explain how genetic variations alter dependence susceptibility. Identification of the specific genes involved in these processes would help to identify individuals that are vulnerable to dependence/addiction and to devise novel treatment strategies.

Typologies of drug dependence: comparative validity of a multivariate and four univariate models

Data from a longitudinal cohort study were used to directly compare the concurrent and predictive validity of four univariate typologic approaches with a multivariate approach in subtyping drug dependence. The four univariate typologies were based upon: (a) age-of-onset of drug abuse/dependence, (b) presence of drug abuse in first-degree relatives, (c) presence of antisocial personality disorder, and (d) sex. The multivariate typologic approach was based on indices of vulnerability, chronicity, consequences, and psychopathology, yielding the Type A/B dichotomy first demonstrated in alcohol dependence. Subtypes generated from the univariate typologies were then each compared with the multivariate typology on measures of concurrent and predictive validity, and the strength of association was compared statistically. There was evidence of significantly greater concurrent validity of the Type A/B typology compared with the univariate typologies across all the domains of validation (risk, substance use, psychopathology, personality, and overall functioning). The multivariate typology also fared better than the univariate ones in all three domains on which predictive validity was evaluated: substance use, psychopathology, and overall functioning, as well as the degree of change in several composite scores (drug, medical, legal, and psychiatric) and the global psychiatric symptom index. This direct method of comparison seemed to demonstrate the superior validity of the multivariate cluster-analytic approach over the univariate approaches to classifying subjects with drug dependence.

A classification of substance-dependent men on temperament and severity variables

This study examined the validity of classifying substance abusers based on temperament and dependence severity, and expanded the scope of typology differences to proximal determinants of use (e.g., expectancies, motives). Patients were interviewed about substance use, depression, and family history of alcohol and drug abuse. Self-report instruments measuring temperament, expectancies, and motives were completed. Participants were 147 male veterans admitted to inpatient substance abuse treatment at a U.S. Department of Veterans Affairs medical center. Cluster analysis identified four types of users with two high substance problem severity and two low substance problem severity groups. Two, high problem severity, early onset groups differed only on the cluster variable of negative affectivity (NA), but showed differences on antisocial personality characteristics, hypochondriasis, and coping motives for alcohol. The two low problem severity groups were distinguished by age of onset and positive affectivity (PA). The late onset, low PA group had a higher incidence of depression, a greater tendency to use substances in solitary contexts, and lower enhancement motives for alcohol compared to the early onset, high PA cluster. The four-cluster solution yielded more distinctions on external criteria than the two-cluster solution. Such temperament variation within both high and low severity substance abusers may be important for treatment planning.

Searching for universals: preliminary evidence for the validity of substance abuse subtypes in a sample of Mexican American youths

Recent studies of substance abuse typologies indicate that multivariate models originally developed for identifying subtypes of alcoholics are valid among users of other substances, including heroin, cocaine, and marijuana. Little is known regarding the generalizability of these subtypes across culturally different subgroups. If substance abuse typologies are universal, then controlling for subtype may prove to be an effective research strategy in studies attempting to distinguish the separate and specific contribution of culturally related factors to risk for substance use and to treatment response. In this article, we present data that replicate the Type A-Type B distinction, developed by Babor et al., in a sample of Hispanic youths with substance involved problems.

A multi-site study of alcohol subtypes: classification and overlap of unidimensional and multi-dimensional typologies

AIMS

The current study examined the usefulness of four prevailing alcohol typologies, assessed in terms of replicability of the multi-dimensional schemas, percentage of the sample classified by each typology, distribution of subtypes by gender and treatment site and construct validity of Type 1/Type 2. In addition, overlap of classification systems was examined to determine whether the four typologies may be narrowed to a smaller set of meaningful, non-redundant subtype schemas.

DESIGN

Baseline data from five treatment outcome studies were used to facilitate subtyping according to four alcohol typologies: antisocial (ASP) versus non-ASP, early versus late onset, Type 1/Type 2 and Type A/Type B.

SETTING

The studies were conducted at several in-patient and out-patient treatment sites.

PARTICIPANTS

The sample included 342 participants (23% female) who met DSM-III-R criteria for alcohol abuse or dependence.

MEASUREMENTS

Subjects were assessed on substance use severity, family history, psychopathology, personality and psychosocial functioning.

FINDINGS

Type 1/Type 2 and Type A/B typologies were replicated. Type 1/Type 2 had poor construct validity due to symptom cluster overlap between the two subgroups. Only 14% of the subjects met criteria for ASP. The two strongest associations including that between early versus late onset and Type 1/Type 2 and that between ASP versus non-ASP and Type A/Type B, were expected and reflect overlaps in conceptual definitions. In comparison, the relationship between early versus late onset and ASP versus non-ASP and Type A/B was weak.

CONCLUSIONS

Clinical utility of the ASP/non-ASP typology is limited in non-Veterans Administration (VA) samples, due to low prevalence. The Type 1/Type 2 subtyping schema was redundant with the age of onset schema, and was the least internally valid of all four typologies. In general, the Type A/B schema was most promising of prevailing typologies studied. It was relatively inclusive, and the A, B groups were distinct from one another. However, dichotomous typologies may not be complex enough to be clinically useful descriptors of alcoholic samples. Aside from ASP and Type B, there appears to be heterogeneity within groups typically considered homogeneous, such as 'early versus late onset' alcoholics.

The relationship of early-onset regular smoking to alcohol use, depression, illicit drug use, and other risky behaviors during early adolescence: results from the youth supplement to the third national health and nutrition examination survey

PURPOSE

Recently we found that the early onset of regular tobacco use is as predictive of lifetime drug use and depressive disorders as it is of alcohol use disorders [Alcohol.: Clin. Exp. Res. 23 (1999) 513.]. This finding, which paralleled findings regarding early onset of alcohol use [J. Subst. Abuse 10 (1998) 59.], suggested that early regular use of any drug might simply be an indicator of risk for a constellation of problem behaviors. The purpose of the present study is to test this hypothesis as well as to study the strength and patterns of associations among these problem behaviors already present among youth. The results will permit description of more precise profiles to identify groups of children at risk.

METHODS

Using data for respondents aged 12-16 from the Third National Health and Nutrition Examination Survey (NHANES III), descriptive statistics were calculated and logistic regression models were estimated.

RESULTS

Descriptive analyses indicated that in comparison with those who never smoked, or who simply experimented, early-onset regular smokers, both those who began at age 13 or younger and those who did so between 14 and 16, were those most likely to use alcohol and other drugs as well as have school problems and early sexual experiences culminating in pregnancy. Multivariate logistic regression analyses were conducted to assess the associations among these high-risk behaviors.

IMPLICATIONS

These results support the hypothesis that early onset of smoking is but an indicator of a syndrome of problem behaviors already in place during childhood. They also suggest that the significance of an age onset variable may differ depending on the age of the sample used. As follow-up data are collected, we expect to learn much about the natural course of the distinct risk groups identified in the analyses by studying longitudinally this nationally representative group of early adolescents.

MMPI-2 typology of pregnant drug-dependent women in treatment

The present study examined the validity of Minnesota Multiphasic Personality Inventory-2 (MMPI-2) typology for pregnant drug-dependent women. A 3-cluster solution based on 7 MMPI-2 clinical scales emerged as the best model and was replicated across split-half samples and different primary substance-use diagnoses and treatment modalities. The 3 subtypes identified included Type I (n = 40, 24%) with no clinical elevation, Type II (n = 72, 42%) with elevated psychopathic deviate scale, and Type III (n = 58, 34%) with elevations on all 7 scales. Analyses with interview and self-report measures showed good concurrent validity. Type II had higher retention than Type I and Type III across methadone and medication-free treatments, showing some predictive validity. An a priori method for classifying new cases on the basis of the proposed typology was developed and validated. Study findings support MMPI-2's use with pregnant drug-dependent women for assessment and possibly treatment planning.

Personality profile and neuropsychological test performance in chronic cocaine-abusers

Little is known about the association between personality disorders and neuropsychological test performance in chronic cocaine users. The aims of the present study were to (1) pinpoint the specific neuropsychological characteristics of chronic cocaine abusers, (2) analyze their personality profile, and (3) explore the association between personality traits and neuropsychological test performance. A sample of 42 drug-abusers (mean age = 34.15; SD = 6.73; mean educational level = 11.44; SD = 2.01) was selected from a state rehabilitation facility and was compared to a control group (mean age = 34.53; SD = 9.01; mean educational level = 12.29; SD = 1.31). The following information was collected for each subject: (1) A clinical history adapted from Horton (1996). (2) The Personality Assessment Inventory (PAI) (Morey, 1991). (3) A neuropsychological test battery including: Arithmetic and Digits subtests from the WAIS-R, California Verbal Learning Test, Trial Making Test, Verbal Fluency tests, Rey-Osterrieth Complex Figure, Wisconsin Card Sorting Test, Benton Visual Retention Test, Stroop Neurological Screening Test and Hooper Visual Organization. Thirty-seven of the drug-dependent subjects obtained an abnormal score in at least one PAI scale. The personality profile of the drug-dependent subjects found via the PAI pointed to a Borderline/Antisocial personality, frequently associated with mania features. In six of the drug-abusers, a normal personality profile was observed. Neuropsychological test performance scores were within the low average or borderline range. The most abnormal scores were observed in attention, memory, and executive functioning tests. The results did not show any robust association between personality profile and neuropsychological test performance.

Reliability and discriminant validity of the Type I/II and Type A/B alcoholic subtype classifications in untreated problem drinkers: a test of the Apollonian--Dionysian hypothesis

The present study tested the hypothesis that there are two broad groups of problem drinkers: the Apollonian-Dionysian distinction. Apollonian drinkers are defined by a later onset of alcohol problems, a slower developmental course, and less problem severity. Dionysian drinkers are defined by more severe alcohol problems, an earlier onset, and worse prognosis. The discriminant validity and classification agreement of five operations of the Apollonian-Dionysian model were tested in a general population (n=8643) and community sample (n=664). A kappa-means cluster analysis supported the Apollonian-Dionysian distinction. Dionysian problem drinkers were more likely to be males, report greater alcohol consumption, more alcohol related antisocial behavior, have a current DSM-IV alcohol dependence diagnosis, and comorbid depression. Apollonian problem drinkers were more prevalent in the general population and reported less severe drinking problems. Classification agreement was stronger for subtype models that incorporate dimensions of alcohol use and/or the frequency of negative consequences. Babor's Type A-Type B model demonstrated the strongest reliability and consistency over time.

Using cluster analysis of alcohol use disorders to investigate 'diagnostic orphans': subjects with alcohol dependence symptoms but no diagnosis

The purpose of this paper is to examine the characteristics of community subjects with one or two alcohol dependence symptoms who did not satisfy the criteria for Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) alcohol dependence or abuse (sub-diagnostic group or diagnostic orphans). Variables not included in the DSM-IV alcohol abuse and dependence criteria are used to compare the different alcohol statuses. The results indicate that the sub-diagnostic group 'diagnostic orphans' formed a cluster distinct from that of the non-problem drinkers group, and appeared to be closer to those with alcohol abuse than to those with alcohol dependence. The diagnosis of DSM-IV alcohol dependence (with three, four, or five or more symptoms) appeared to be its own entity. The findings lend credence to the requirement of three symptoms (in any 12 months) for the diagnosis of alcohol dependence in DSM-IV. However, those with one or two symptoms of alcohol dependence should be considered along with alcohol abuse as an entity in future DSM classifications.

Psychiatric comorbidity in white and African-American illicit substance abusers: evidence for differential etiology

Research on psychiatric comorbidity among opiate and cocaine addicts has consistently found African-Americans to report fewer symptoms of anxiety and affective disorders than Whites. The current article reviews the research on these racial differences, evaluates various interpretations of these differences, and discusses the limitations of past research. It is concluded that Whites and African-American addicts differ in their underlying reasons for abusing drugs. Drug addiction among Whites appears to be related largely to psychopathology, whereas Black drug abuse is best understood in terms of social and environmental factors. Treatment implications are also discussed.

Multidimensional subtypes and treatment outcome in first-time DWI offenders

The concurrent and predictive validity of Type A and B alcoholism subtypes was evaluated in 246 first-time driving-while-intoxicated (DWI) offenders. K-means analysis indicated that a two-cluster solution was optimal with Type Bs (28%) exhibiting greater premorbid risk factors, alcohol and psychosocial severity, drinking consequences, psychopathology, higher stage of change, and less coping confidence in comparison to less severe Type As (72%). After baseline assessment, participants were randomly assigned to one of three 10-week group treatments (DWI Education, Coping Skills, Interactional), and reassessed at termination, and at 6-month and 1-year follow-ups. Type B was associated with more severe symptoms after treatment, but there was no evidence for patient-treatment matching effects. Although Type A/B may be an important theoretical model for guiding alcoholism research, it usefulness and efficiency for treatment matching, planning, or placement purposes is questioned.

Temperament Style and Substance Abuse Characteristics

The relationship of temperament to different patterns and types of alcohol abuse has received much attention over the last decade in order to provide clues to matching patients optimally to treatment strategies. The purpose of this study was to examine the relationship of temperament with a number of relevant substance abuse characteristics in a substance abusing population. One hundred forty-five male veterans were interviewed on their lifetime use of substances and on their psychiatric symptoms, problems associated with use, context, and family history of substance abuse. Subjects filled out the TPQ and the MPQ, which were subjected to factor analysis and revealed four factors: (1) Negative Affectivity/Impulsivity, (2) Positive Affectivity/Sociability, (3) Persistence/Achievement, and (4) Constraint. There was partial support for the hypotheses. Impulsivity was negatively correlated with age of onset and positively correlated with substance-related problems and a family history of substance abuse. Subjects with a history of depression scored significantly lower on the Positive Affectivity/Sociability factor than those who had not experienced a significant depression. Individuals who used alone scored lower on this factor than those who used in social contexts. The temperament factors of Persistence/Achievement and Constraint were, for the most part, unrelated to substance abuse.

Fluoxetine treatment seems to reduce the beneficial effects of cognitive-behavioral therapy in type B alcoholics

OBJECTIVE

The aim of this study was to test the hypothesis that, because of abnormalities in serotonergic neurotransmission that may underlie craving and impulsive behavior, fluoxetine treatment differentially affects drinking among type B alcoholics, who are characterized by high levels of both premorbid vulnerability and alcohol-related problems.

METHODS

Using a k-means clustering procedure, alcohol-dependent subjects from a placebo-controlled trial of fluoxetine were grouped into low-risk/severity (type A: n = 60) and high-risk/ severity (type B: n = 35) groups. Multivariate analysis of covariance (with pretreatment measures as covariates) evaluated the effects of Alcoholic Subtype, Medication Group, Treatment Completion, and their interactions on measures of drinking, both during the 12-week treatment period and a 6-month follow-up period.

RESULTS

Although there were no main effects of Alcoholic Subtype or Medication Group, subjects who completed the treatment trial showed significantly better drinking-related outcomes. There was also an interaction of Alcoholic Subtype by Medication Group during treatment. Among type B subjects, fluoxetine treatment resulted in poorer drinking-related outcomes than placebo treatment. Among type A subjects, there was no effect of Medication Group. This interactive effect did not persist during the 6-month follow-up period.

CONCLUSIONS

Alcoholic subtypes identified by cluster analysis seem to be differentially responsive to the effects of fluoxetine treatment on drinking-related outcomes. Serotonergic abnormalities previously identified among a subgroup of alcoholics who are also characterized by impulsivity and severity of alcohol dependence may help to explain the differential medication effect. Based on these findings, it is recommended that, in the absence of a comorbid mood or anxiety disorder, fluoxetine not be used to maintain abstinence or reduce drinking in high-risk/severity alcoholics.