The latent structure of marijuana and cocaine use disorders: results from the National Longitudinal Alcohol Epidemiologic Survey (NLAES)

Cocaine use disorder criteria in a clinical sample: an analysis using item response theory, factor and network analysis

BACKGROUND

The conceptualization of substance use disorders (SUDs) was modified in successive editions of the DSM. Dimensionality and inclusion/exclusion of several criteria was studied using various analytic approaches.

OBJECTIVE

The study aimed to deepen our knowledge of the interrelationships between the diagnostic criteria for cocaine use disorder (CUD), applying three different analytical techniques: factor analysis, Item Response Theory (IRT) models, and network analysis.

METHODS

425 (85.4% male) outpatients were evaluated for CUD using the Substance Dependence Severity Scale. Confirmatory Factor Analysis, 2-parameter logistic model (IRT) and network analysis were applied to analyze the relationships between the diagnostic criteria.

RESULTS

The results show that "legal problems" criterion is not congruent with the CUD measure on three analyses. Also, network analysis suggests the usefulness of the "craving" criterion. The criterion "quit/control" is the one that presents the best centrality indices and expected influence, showing strong relationships with the criteria of "craving," "tolerance," "neglect roles" and "activities given up."

CONCLUSIONS

Network analysis appears to be a useful and complementary technique to factor analysis and IRT for understanding CUD. The "quit/control" criterion emerges as a central criterion to understand CUD.

Evaluation of a Mobile Device Survey System for Behavioral Risk Factors (SHAPE): App Development and Usability Study

Background

Risk factors, including limited exercise, poor sleep, smoking, and alcohol and drug use, if mitigated early, can improve long-term health. Risk prevalence has traditionally been measured using methods that now have diminished participation rates. With >75% of American citizens owning smartphones, new data collection methods using mobile apps can be evaluated.

Objective

The objective of our study was to describe the development, implementation, and evaluation of a mobile device–based survey system for behavioral risk assessment. Specifically, we evaluated its feasibility, usability, acceptability, and validity.

Methods

We enrolled 536 students from 3 Vermont State Colleges. Iterative mobile app development incorporated focus groups, extensive testing, and the following 4 app versions: iOS standard, iOS gamified, Android standard, and Android gamified. We aimed to capture survey data, paradata, and ambient data such as geolocation. Using 3 separate surveys, we asked a total of 27 questions that included demographic characteristics, behavioral health, and questions regarding the app’s usability and survey process.

Results

Planned enrollment was exceeded in just a few days. There were 1392 “hits” to the landing page where the app could be downloaded. Excluding known project testers and others not part of the study population, 670 participants downloadeded the SHAPE app. Of those, 94.9% of participants (636/670) agreed to participate by providing in-app consent. Of the 636 who provided consent, 84.3% (536/636) were deemed eligible for the study. The majority of eligible respondents completed the initial survey (459/536, 85.6%), whereas 29.9% (160/536) completed the second survey and 28.5% (153/536) completed the third survey. The SHAPE survey obtained 414 participants on the behavioral risk items in survey 1, which is nearly double the 209 participants who completed the traditional Vermont College Health Survey in 2014. SHAPE survey responses were consistent with the traditionally collected Vermont College Health Survey data.

Conclusions

This study provides data highlighting the potential for mobile apps to improve population-based health, including an assessment of recruitment methods, burden and response rapidity, and future adaptations. Although gamification and monetary rewards were relatively unimportant to this study population, item response theory may be technologically feasible to reduce individual survey burden. Additional data collected by smartphones, such as geolocation, could be important in additional analysis, such as neighborhood characteristics and their impact on behavioral risk factors. Mobile tools that offer rapid adaptation for specific populations may improve research data collection for primary prevention and could be used to improve engagement and health outcomes.

The National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) Waves 1 and 2: review and summary of findings

PURPOSE

The NESARC, a "third-generation" psychiatric epidemiologic survey that integrated detailed measures of alcohol and drug use and problems has been the data source for over >850 publications. A comprehensive review of NESARC findings and their implications is lacking.

METHOD

NESARC was a survey of 43,093 participants that covered alcohol, drug and psychiatric disorders, risk factors, and consequences. Wave 1 of the NESARC was conducted in 2001-2002. Three years later, Wave 2 follow-up re-interviews were conducted with 34,653 of the original participants. Scopus and Pubmed were used to search for NESARC papers, which were sorted into topic areas and summarized.

RESULT

The most common disorders were alcohol and posttraumatic stress disorders, and major depression. Females had more internalizing disorders and males had more externalizing disorders, although the preponderance of males with alcohol disorders (the "gender gap") was less pronounced than it was in previous decades. A race/ethnic "paradox" (lower risk among disadvantaged minorities than whites) remains unexplained. Younger participants had higher risk for substance and personality disorders, but not unipolar depressive or anxiety disorders. Psychiatric comorbidity was extensive and often formed latent trans-diagnostic domains. Since 1991-1992, risk for marijuana and prescription drug disorders increased, while smoking decreased, although smoking decreases were less pronounced among those with comorbidity. A nexus of comorbidity, social support, and stress predicted transitions in diagnostic status between Waves 1 and 2. Childhood maltreatment predicted psychopathology. Alcohol and drug use disorders were seldom treated; attitudinal barriers (little perceived need, perceived alcoholism stigma, pessimism about efficacy) were more important in predicting non-treatment than financial barriers.

CONCLUSIONS

Understanding comorbidity and the effects of early stressors will require research incorporating biologic components, e.g., genetic variants and brain imaging. The lack of treatment for alcohol and drug disorders, predicted by attitudinal rather than financial variables, suggests an urgent need for public and professional education to reduce the stigma associated with these disorders and increase knowledge of treatment options.

Natural course of cannabis use disorders

BACKGROUND

Despite its importance as a public health concern, relatively little is known about the natural course of cannabis use disorders (CUDs). The primary objective of this research was to provide descriptive data on the onset, recovery and recurrence functions of CUDs during the high-risk periods of adolescence, emerging adulthood and young adulthood based on data from a large prospective community sample.

METHOD

Probands (n = 816) from the Oregon Adolescent Depression Project (OADP) participated in four diagnostic assessments (T1-T4) between the ages of 16 and 30 years, during which current and past CUDs were assessed.

RESULTS

The weighted lifetime prevalence of CUDs was 19.1% with an average onset age of 18.6 years. Although gender was not significantly related to the age of initial CUD onset, men were more likely to be diagnosed with a lifetime CUD. Of those diagnosed with a CUD episode, 81.8% eventually achieved recovery during the study period. Women achieved recovery significantly more quickly than men. The recurrence rate (27.7%) was relatively modest, and most likely to occur within the first 36 months following the offset of the first CUD episode. CUD recurrence was uncommon after 72 months of remission and recovery.

CONCLUSIONS

CUDs are relatively common, affecting about one out of five persons in the OADP sample prior to the age of 30 years. Eventual recovery from index CUD episodes is the norm, although about 30% of those with a CUD exhibit a generally persistent pattern of problematic use extending 7 years or longer.

Latent class analysis of DSM-5 criteria for opioid use disorders: results from the Iranian National Survey on Mental Health

BACKGROUND

Assessments of DSM-IV and DSM-5 criteria with sample populations of opioid users are limited. This study aimed to determine the number of latent classes in opioid users and assessment of the proposed revisions to the DSM-5 opioid use disorder (OUD) criteria.

METHODS

Data came from the 2011 Iranian National Mental Health Survey (IranMHS) on 7,886 participants aged 15-64 years living in Iran. We used the Composite International Diagnostic Interview (CIDI) version 2.1 in all respondents who indicated using opioids at least 5 times in the previous 12 months (n = 236).

RESULTS

A three-class model provided the best fit of all the models tested. Classes showed a spectrum of severity that was compatible with the DSM-5 classification. 'Legal problems' and 'desire to cut down' showed poor discrimination between classes. The weighted prevalence of OUD using DSM-5 was 20.7% higher than with DSM-IV.

CONCLUSIONS

RESULTS support the grouping based on severity of symptoms, combining abuse and dependence into a single diagnosis, omitting legal problems, and addition of craving as a new criterion.

DSM-5 criteria for substance use disorders: recommendations and rationale

Since DSM-IV was published in 1994, its approach to substance use disorders has come under scrutiny. Strengths were identified (notably, reliability and validity of dependence), but concerns have also arisen. The DSM-5 Substance-Related Disorders Work Group considered these issues and recommended revisions for DSM-5. General concerns included whether to retain the division into two main disorders (dependence and abuse), whether substance use disorder criteria should be added or removed, and whether an appropriate substance use disorder severity indicator could be identified. Specific issues included possible addition of withdrawal syndromes for several substances, alignment of nicotine criteria with those for other substances, addition of biomarkers, and inclusion of nonsubstance, behavioral addictions.This article presents the major issues and evidence considered by the work group, which included literature reviews and extensive new data analyses. The work group recommendations for DSM-5 revisions included combining abuse and dependence criteria into a single substance use disorder based on consistent findings from over 200,000 study participants, dropping legal problems and adding craving as criteria, adding cannabis and caffeine withdrawal syndromes, aligning tobacco use disorder criteria with other substance use disorders, and moving gambling disorders to the chapter formerly reserved for substance-related disorders. The proposed changes overcome many problems, while further studies will be needed to address issues for which less data were available.

Relationship of substance abuse to dependence in the U.S. general population

OBJECTIVE

The diagnostic categories of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, for substance abuse and dependence are commonly used in clinical work and research studies, but whether abuse and dependence represent two different syndromes has been debated. The purpose of this article is to investigate the relationship of substance abuse and dependence for cannabis, cocaine, stimulants and sedatives among lifetime users of these substances in the National Epidemiologic Survey on Alcohol and Related Conditions, a nationally representative survey conducted in 2001-2002.

METHOD

The multiple indicators multiple causes (MIMIC) model addresses three sets of relationships: those between (1) diagnostic criteria and latent factors, (2) latent factors and covariates, and (3) criteria and covariates. This approach allows for the detection of and compensation for noninvariance of the measurement of criteria across subgroups.

RESULTS

Compared with one-factor models, two-factor models (factors roughly corresponding to abuse and dependence) fit significantly better across all substances, with abuse and dependence factors highly correlated. The MIMIC model indicated that race/ethnicity, age, income, and marital status showed some differential relationships across substance groups, although most covariates showed similar associations to dependence and abuse factors. Noninvariance of criteria measurement by demographic covariates was most pronounced for cannabis abuse and dependence criteria.

CONCLUSIONS

The general relationship of abuse to dependence was consistent across substances. Results were equivocal on the value of retaining separate factors; therefore, investigating the relationships of specific genetic variants and treatment outcomes to dimensional indicators of abuse, dependence, and measures combining these criteria is warranted. Measurement of cannabis abuse and dependence criteria appears most affected by demographic characteristics.

A dimensional approach to understanding severity estimates and risk correlates of marijuana abuse and dependence in adults

While item response theory (IRT) research shows a latent severity trait underlying response patterns of substance abuse and dependence symptoms, little is known about IRT-based severity estimates in relation to clinically relevant measures. In response to increased prevalences of marijuana-related treatment admissions, an elevated level of marijuana potency, and the debate on medical marijuana use, we applied dimensional approaches to understand IRT-based severity estimates for marijuana use disorders (MUDs) and their correlates while simultaneously considering gender- and race/ethnicity-related differential item functioning (DIF). Using adult data from the 2008 National Survey on Drug Use and Health (N = 37,897), Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria for MUDs among past-year marijuana users were examined by IRT, logistic regression, and multiple indicators-multiple causes (MIMIC) approaches. Among 6917 marijuana users, 15% met criteria for a MUD; another 24% exhibited subthreshold dependence. Abuse criteria were highly correlated with dependence criteria (correlation = 0.90), indicating unidimensionality; item information curves revealed redundancy in multiple criteria. MIMIC analyses showed that MUD criteria were positively associated with weekly marijuana use, early marijuana use, other substance use disorders, substance abuse treatment, and serious psychological distress. African Americans and Hispanics showed higher levels of MUDs than Whites, even after adjusting for race/ethnicity-related DIF. The redundancy in multiple criteria suggests an opportunity to improve efficiency in measuring symptom-level manifestations by removing low-informative criteria. Elevated rates of MUDs among African Americans and Hispanics require research to elucidate risk factors and improve assessments of MUDs for different racial/ethnic groups.

Compatibility of current DSM-IV and proposed DSM-5 diagnostic criteria for cocaine use disorders

OBJECTIVES

The present study examined the compatibility of the current DSM-IV and proposed DSM-5 diagnostic criteria for cocaine use disorders (CUD) among state prison inmates, and evaluated the diagnostic utility of the proposed criteria in accounting for DSM-IV "diagnostic orphans" (i.e., individuals who meet one or two of the diagnostic criteria for substance dependence yet fail to report indications of substance abuse).

METHOD

Data were derived from routine clinical assessments of adult male inmates (N=6871) recently admitted to the Minnesota Department of Corrections state prison system from 2000 to 2003. An automated (i.e., computer-prompted) version of the Substance Use Disorder Diagnostic Schedule-IV (SUDDS-IV; Hoffmann & Harrison, 1995) was administered to all inmates as part of routine assessments. DSM-IV and DSM-5 criteria were coded using proposed guidelines.

RESULTS

The past 12-month prevalence of DSM-IV CUDs was 12.7% (Abuse, 3.8%, Dependence, 8.9%), while 11.0% met past 12-month DSM-5 criteria for a CUD (Moderate [MCUD], 1.7%; Severe [SCUD], 9.3%). When DSM-5 criteria were applied, 11.8% of the DSM-IV diagnostic orphans received a MCUD diagnosis. The vast majority of those with no diagnosis (99.6%) continued to have no diagnosis, and a similar proportion who met dependence criteria (98.4%) met SCUD criteria of the proposed DSM-5. Most of the variation in diagnostic classifications was accounted for by those with a current abuse diagnosis.

CONCLUSIONS

The proposed DSM-5 criteria perform similarly to DSM-IV criteria in terms of the observed past 12-month CUD prevalence and diagnostic classifications. The proposed criteria appear to account for diagnostic orphans that may warrant a diagnosis. DSM-IV abuse cases were most affected when DSM-5 criteria were applied. Additional criteria, beyond those included in the proposed DSM-5 changes, concerning use to relieve emotional stress and preoccupation with use were frequently endorsed by those with a proposed DSM-5 diagnosis.

Item response theory analysis of DSM-IV criteria for inhalant-use disorders in adolescents

OBJECTIVE

Inhalants are a serious public health concern and a dangerous form of substance use. An important unresolved issue in the inhalant literature concerns the validity of inhalant-use diagnoses and the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, distinction between inhalant abuse and inhalant dependence. To address these limitations and provide the foundation for helping build stronger diagnostic and assessment tools related to inhalant problems, this study examined the dimensionality of the criteria set and the abuse-dependence distinction using item response theory (IRT) analysis.

METHOD

This study used data from a survey of the population of Missouri Division of Youth Services' residents of the residential treatment system. The current study focused on adolescents and young adults who reported a lifetime history of inhalant use (N = 279).

RESULTS

The results from the IRT analysis showed no consistent hierarchical ordering of abuse and dependence criteria, providing strong evidence against the abuse-dependence distinction. The abuse criterion of legal problems associated with use represented the item with the highest level of inhalant severity. The dependence criterion that was related to giving up important social, occupational, or recreational activities provided the most accurate discrimination between individuals at different levels of severity.

CONCLUSIONS

Inhalant-use disorders are best represented using a dimensional versus a categorical approach. IRT analysis provides guidance for selecting criteria that can be useful for brief assessments of inhalant-use problems.

Opioid dependence latent structure: two classes with differing severity?

AIMS

To examine the structure of illicit opioid abuse and dependence within an opioid dependent sample and its relationship to other clinical variables.

DESIGN, SETTING AND PARTICIPANTS

A cross-sectional study of 1511 opioid dependent individuals recruited through opioid pharmacotherapy clinics in the Sydney area, Australia.

MEASUREMENTS

A face-to-face structured interview covering substance use and dependence, psychiatric history, child maltreatment, family background, adult violence and criminal history. Dimensional, latent class and factor mixture models were fit to the opioid abuse and dependence data. Classes were then compared on a range of demographic and clinical covariates.

FINDINGS

A two-class, one-factor model provided the best fit of all the models tested. The two classes differed with respect to endorsement probabilities on a range of abuse and dependence criteria, and also with respect to the odds of other drug dependence diagnoses, antisocial personality disorder and non-fatal opioid overdose. Within-class severity was associated with similar variables: other drug dependence, borderline personality disorder and opioid overdose.

CONCLUSION

In an in-treatment, opioid-dependent sample, there appears to be two classes of individuals exhibiting distinct patterns of abuse and dependence criteria endorsement and to differ on externalizing but not internalizing disorders. This study provides preliminary evidence that the proposed DSM-V opioid use disorder distinction between moderate and severely dependent people is valid. Class one participants were not only more severely dependent, but had greater odds for opioid overdoses, other drug dependence and antisocial personality disorder.

Cannabis dimensionality: dependence, abuse and consumption

AIMS

Genetic research on substance use disorders usually defines phenotypes as a binary diagnosis, resulting in a loss of information if the disorder is inherently dimensional. The DSM-IV criteria for drug dependence were based on a theoretically dimensional (linear) model. Considerable investigation has been conducted on DSM-IV alcohol criteria, but less is known about the dimensionality of DSM-IV cannabis criteria for abuse and dependence. The aim of this study is to assess whether DSM-IV cannabis dependence (including withdrawal) and abuse criteria fit a linear measure of severity and whether a consumption criterion adds linearly to severity.

DESIGN/SETTING/PARTICIPANTS/MEASUREMENTS

Participants were 8172 in the National Epidemiologic Survey on Alcohol and Related Conditions who had ever used cannabis. Wald statistics were used to test whether categorical, dimensional or hybrid forms best fit the data. We examined the following as criterion sets: (1) dependence; (2) dependence and abuse; and (3) dependence, abuse and frequency of use. Validating variables included family history of drug problems, early onset of cannabis use, and antisocial personality disorder.

FINDINGS

For cannabis dependence, no evidence was found for categorical or hybrid models; Wald tests indicated that models representing the seven DSM-IV dependence criteria as a linear severity measure best described the association between the criteria and validating variables. However, significant differences from linearity occurred after adding the four cannabis abuse criteria (p=0.03) and the use indicator (p=0.01) for family history and antisocial personality disorder.

CONCLUSION

With ample power to detect non-linearity, cannabis dependence was shown to form an underlying continuum of severity. However, adding abuse criteria, with and without a measure of consumption, resulted in a model that differed significantly from linearity for two of the three validating variables.

Using a latent variable approach to inform gender and racial/ethnic differences in cocaine dependence: a National Drug Abuse Treatment Clinical Trials Network study

This study applies a latent variable approach to examine gender and racial/ethnic differences in cocaine dependence, to determine the presence of differential item functioning (DIF) or item-response bias to diagnostic questions of cocaine dependence, and to explore the effects of DIF on the predictor analysis of cocaine dependence. The analysis sample included 682 cocaine users enrolled in two national multisite studies of the National Drug Abuse Treatment Clinical Trials Network (CTN). Participants were recruited from 14 community-based substance abuse treatment programs associated with the CTN, including 6 methadone and 8 outpatient nonmethadone programs. Factor and multiple indicators-multiple causes (MIMIC) procedures evaluated the latent continuum of cocaine dependence and its correlates. MIMIC analysis showed that men exhibited lower odds of cocaine dependence than women (regression coefficient, beta = -0.34), controlling for the effects of DIF, years of cocaine use, addiction treatment history, comorbid drug dependence diagnoses, and treatment setting. There were no racial/ethnic differences in cocaine dependence; however, DIF by race/ethnicity was noted. Within the context of multiple community-based addiction treatment settings, women were more likely than men to exhibit cocaine dependence. Addiction treatment research needs to further evaluate gender-related differences in drug dependence in treatment entry and to investigate how these differences may affect study participation, retention, and treatment response to better serve this population.

Item response theory analysis of lifetime cannabis-use disorder symptom severity in an American Indian community sample

OBJECTIVE

The aim of this study was to use Item Response Theory to assess Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised (DSM-III-R), lifetime cannabis-use disorder (CUD) symptom severity and its relationship to first cannabis use before age 15 years, male gender, and childhood conduct disorder in an American Indian community sample.

METHOD

The Semi-Structured Assessment for the Genetics of Alcoholism was used to determine demographic information, age at first use, and DSM-III-R childhood conduct disorder and lifetime CUD symptoms in a community sample of 349 American Indian participants who had used cannabis at least 21 times in a single year. Two-parameter Item Response Theory models generated marginal maximum likelihood estimates for discrimination (a) and threshold (b) parameters for nine DSM-III-R CUD symptoms along an underlying latent CUD severity continuum. Differential Item Functioning (DIF) analysis was used to assess for differences in symptom severity in groups defined by presence versus absence of age at first use before 15 years, male gender, and childhood conduct disorder.

RESULTS

CUD symptoms of "use in larger amounts or over longer periods of time," "activities given up," and "role failure" were the most severe symptoms. All CUD symptoms fell on the moderate portion of the severity continuum. "Time spent" was more severe in individuals who first used cannabis after age 15 years, "hazardous use" was more severe in females, and "use in larger amounts or over longer periods of time" was more severe in individuals with co-morbid childhood conduct disorder.

CONCLUSIONS

Specific risk factors for the development of lifetime CUD are associated with increased severity of several CUD symptoms in this high-risk group.

The construct and measurement equivalence of cocaine and opioid dependences: a National Drug Abuse Treatment Clinical Trials Network (CTN) study

INTRODUCTION

Although DSM-IV criteria are widely used in making diagnoses of substance use disorders, gaps exist regarding diagnosis classification, use of dependence criteria, and effects of measurement bias on diagnosis assessment. We examined the construct and measurement equivalence of diagnostic criteria for cocaine and opioid dependences, including whether each criterion maps onto the dependence construct, how well each criterion performs, how much information each contributes to a diagnosis, and whether symptom-endorsing is equivalent between demographic groups.

METHODS

Item response theory (IRT) and multiple indicators-multiple causes (MIMIC) modeling were performed on a sample of stimulant-using methadone maintenance patients enrolled in a multisite study of the National Drug Abuse Treatment Clinical Trials Network (CTN) (N=383). Participants were recruited from six community-based methadone maintenance treatment programs associated with the CTN and major U.S. providers. Cocaine and opioid dependences were assessed by DSM-IV Checklist.

RESULTS

IRT modeling showed that symptoms of cocaine and opioid dependences, respectively, were arrayed along a continuum of severity. All symptoms had moderate to high discrimination in distinguishing drug users between severity levels. "Withdrawal" identified the most severe symptom of the cocaine dependence continuum. MIMIC modeling revealed some support for measurement equivalence.

CONCLUSIONS

Study results suggest that self-reported symptoms of cocaine and opioid dependences and their underlying constructs can be measured appropriately among treatment-seeking polysubstance users.

An item response theory modeling of alcohol and marijuana dependences: a National Drug Abuse Treatment Clinical Trials Network study

OBJECTIVE

The aim of this study was to examine psychometric properties of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), diagnostics criteria for alcohol and marijuana dependences among 462 alcohol users and 311 marijuana users enrolled in two multisite trials of the National Drug Abuse Treatment Clinical Trials Network.

METHOD

Diagnostic questions were assessed by the DSM-IV checklist. Data were analyzed by the item response theory and the multiple indicators-multiple causes method procedures.

RESULTS

Criterion symptoms of alcohol and marijuana dependences exhibited a high level of internal consistency. All individual symptoms showed good discrimination in distinguishing alcohol or marijuana users between high and low severity levels of the continuum. In both groups, "withdrawal" appeared to measure the most severe symptom of the dependence continuum. There was little evidence of measurement nonequivalence in assessing symptoms of dependence by gender, age, race/ethnicity, and educational level.

CONCLUSIONS

These findings highlight the clinical utility of the DSM-IV checklist in assessing alcohol- and marijuana dependence syndromes among treatment-seeking substance users.

Characteristics of DSM-IV alcohol diagnostic orphans: drinking patterns, physical illness, and negative life events

BACKGROUND

Interest in subthreshold psychiatric disorders has increased recently. Diagnostic orphans experience one to two criteria of alcohol dependence but do not meet the diagnostic criteria for a DSM-IV alcohol use disorder (AUD). This study investigated the impact of subthreshold alcohol symptoms on three domains: physical illness, drinking patterns, and the occurrence of negative life events.

METHOD

Current drinkers (n=26,946) in the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) were divided into five diagnosis groups: no-AUD; one-criterion orphans (reference group), two-criterion orphans, alcohol abuse, and alcohol dependence. Exploratory factor analysis examined the factor structure of items in the Alcohol Use Disorders and Associated Disabilities Interview Schedule (AUDADIS-IV) relating to each life domains. Factors were related to the diagnosis groups and background covariates using latent variable modeling.

RESULTS

One-criterion orphans did not differ from the other groups with regards to physical illness. One- and two-criterion orphans differed significantly in relation to drinking patterns, with the latter group engaging in hazardous drinking behaviours more frequently. The dependence group were more likely to experience higher estimates of social problems compared to one-criterion orphans. One-criterion orphans were more likely than the abuse group to experience financial problems but less likely than the dependence group to experience family-related legal problems.

CONCLUSIONS

Diagnostic orphans were more impaired than those with no-AUD or alcohol abuse in specific life domains; however, diagnostic orphans were significantly less impaired than those with alcohol dependence. Diagnostic orphans may be an important group for early case identification and intervention.

DSM-IV criteria-based clinical subtypes of cannabis use disorders: results from the National Epidemiological Survey on Alcohol and Related Conditions (NESARC)

Prior research documented high homogeneity of alcohol use disorders (AUDs) as clinical entities. However, it is unknown whether this finding extends to other substance use disorders. We investigated this by examining the prevalence of all possible DSM-IV criteria-based clinical subtypes of current and lifetime cannabis use disorders in the general population. The number of possible (i.e., theoretical) clinical subtypes of cannabis abuse and dependence based on different combinations of the DSM-IV criteria was calculated using the combinatorial function. This number was compared with the subtypes actually observed in the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), a large U.S. national sample (N=43,093). Clinical and demographic correlates of the subtypes were examined with chi2 tests whose target population was the United States civilian non-institutionalized population. All DSM-IV cannabis abuse and dependence criteria were assessed with the Alcohol Use Disorder and Associated Disabilities Interview Schedule-DSM-IV Version (AUDADIS-IV). Of all possible cannabis dependence subtypes, 29 (69%) were observed in the 12-month timeframe, and 41 (98%) in the lifetime timeframe. The corresponding numbers of subtypes for cannabis abuse were 12 (75%), current and 15 (100%), lifetime. These findings suggest that, in contrast to alcohol disorders, cannabis use disorders were highly heterogeneous. Future research should investigate whether there are differences in the course and treatment response of these clinical subtypes of cannabis use disorders, and the heterogeneity of other substance use disorders.