Psychometric properties of DSM assessments of illicit drug abuse and dependence: results from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC).
ABSTRACT DSM-IV criteria for illicit drug abuse and dependence are largely based on criteria developed for alcohol use disorders and there is a lack of research evidence on the psychometric properties of these symptoms when applied to illicit drugs.
This study utilizes data on abuse/dependence criteria for cannabis, cocaine, stimulants, sedatives, tranquilizers, opiates, hallucinogens and inhalants from the National Epidemiological Survey on Alcohol and Related Conditions (NESARC, n=43 093). Analyses included factor analysis to explore the dimensionality of illicit drug abuse and dependence criteria, calculation of item difficulty and discrimination within an item response framework and a descriptive analysis of 'diagnostic orphans': individuals meeting criteria for 1-2 dependence symptoms but not abuse. Rates of psychiatric disorders were compared across groups.
Results favor a uni-dimensional construct for abuse/dependence on each of the eight drug classes. Factor loadings, item difficulty and discrimination were remarkably consistent across drug categories. For each drug category, between 29% and 51% of all individuals meeting criteria for at least one symptom did not receive a formal diagnosis of either abuse or dependence and were therefore classified as 'orphans'. Mean rates of disorder in these individuals suggested that illicit drug use disorders may be more adequately described along a spectrum of severity.
While there were remarkable similarities across categories of illicit drugs, consideration of item difficulty suggested that some alterations to DSM regarding the relevant severity of specific abuse and dependence criteria may be warranted.
SourceAvailable from: Thomas S Kubarych[Show abstract] [Hide abstract]
ABSTRACT: Accumulating evidence suggests that the Diagnostic and Statistical Manual of Mental Disorders (DSM) diagnostic criteria for cannabis abuse and dependence are best represented by a single underlying factor. However, it remains possible that models with additional factors, or latent class models or hybrid models, may better explain the data. Using structured interviews, 626 adult male and female twins provided complete data on symptoms of cannabis abuse and dependence, plus a craving criterion. We compared latent factor analysis, latent class analysis, and factor mixture modeling using normal theory marginal maximum likelihood for ordinal data. Our aim was to derive a parsimonious, best-fitting cannabis use disorder (CUD) phenotype based on DSM-IV criteria and determine whether DSM-5 craving loads onto a general factor. When compared with latent class and mixture models, factor models provided a better fit to the data. When conditioned on initiation and cannabis use, the association between criteria for abuse, dependence, withdrawal, and craving were best explained by two correlated latent factors for males and females: a general risk factor to CUD and a factor capturing the symptoms of social and occupational impairment as a consequence of frequent use. Secondary analyses revealed a modest increase in the prevalence of DSM-5 CUD compared with DSM-IV cannabis abuse or dependence. It is concluded that, in addition to a general factor with loadings on cannabis use and symptoms of abuse, dependence, withdrawal, and craving, a second clinically relevant factor defined by features of social and occupational impairment was also found for frequent cannabis use.Twin Research and Human Genetics 03/2014; DOI:10.1017/thg.2014.9 · 1.92 Impact Factor
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ABSTRACT: Alcohol and drug use disorders are individually heritable (50%). Twin studies indicate that alcohol and substance use disorders share common genetic influences, and therefore may represent a more heritable form of addiction and thus be more powerful for genetic studies. This study utilized data from 2322 subjects from 118 European-American families in the Collaborative Study on the Genetics of Alcoholism sample to conduct genome-wide association analysis of a binary and a continuous index of general substance dependence liability. The binary phenotype (ANYDEP) was based on meeting lifetime criteria for any DSM-IV dependence on alcohol, cannabis, cocaine or opioids. The quantitative trait (QUANTDEP) was constructed from factor analysis based on endorsement across the seven DSM-IV criteria for each of the four substances. Heritability was estimated to be 54% for ANYDEP and 86% for QUANTDEP. One single-nucleotide polymorphism (SNP), rs2952621 in the uncharacterized gene LOC151121 on chromosome 2, was associated with ANYDEP (P = 1.8 × 10−8), with support from surrounding imputed SNPs and replication in an independent sample [Study of Addiction: Genetics and Environment (SAGE); P = 0.02]. One SNP, rs2567261 in ARHGAP28 (Rho GTPase-activating protein 28), was associated with QUANTDEP (P = 3.8 × 10−8), and supported by imputed SNPs in the region, but did not replicate in an independent sample (SAGE; P = 0.29). The results of this study provide evidence that there are common variants that contribute to the risk for a general liability to substance dependence.Addiction Biology 06/2014; 20(3). DOI:10.1111/adb.12153 · 5.93 Impact Factor