Item response theory analysis of DSM-IV cannabis abuse and dependence criteria in adolescents

Dimensionality and differential functioning of DSM-5 cannabis use disorder criteria in an online sample of adults with frequent cannabis use

The DSM-5 criteria for cannabis use disorder (CUD) combine DSM-IV dependence and abuse criteria (without legal problems) and new withdrawal and craving criteria. Information on dimensionality, internal reliability, and differential functioning of the DSM-5 CUD criteria is lacking. Additionally, dimensionality of the DSM-5 withdrawal items is unknown. This study examined the psychometric properties of the DSM-5 CUD criteria among adults who used cannabis in the past 7 days (N = 5,119). Adults with frequent cannabis use were recruited from the US general population through social media and filled in a web-based survey about demographics and cannabis use behaviors. Factor analysis was used to assess dimensionality, and item response theory analysis models were used to explore relationships between the criteria and the underlying latent trait (CUD), and whether each criterion and the criteria set functioned differently by demographic and clinical characteristics: sex, age, state-level cannabis laws, reasons for cannabis use, and frequency of use. The DSM-5 CUD criteria showed unidimensionality and provided information about the CUD latent trait across the severity spectrum. The cannabis withdrawal items indicated one underlying latent factor. While some CUD criteria functioned differently in specific subgroups, the criteria set as a whole functioned similarly across subgroups. In this online sample of adults with frequent cannabis use, evidence supports the reliability, validity, and utility of the DSM-5 CUD diagnostic criteria set, which can be used for determining a major risk of cannabis use, i.e., CUD, to inform cannabis policies and public health messaging, and for developing intervention strategies.

Induced negative affect's impact on self-reported cannabis use, expectancies, and problems

Substance use disorders and affective disturbances often covary. Even momentary experiences of negative affect (NA) appear linked with substance use. While strong evidence of these relations exists, NA might bias endorsements of substance use due to hindered recall and reporting processes. This hypothesis warrants further research, as accurate assessment of substance-related variables is crucial in both research and treatment settings. The present study examined the influence of NA on reporting of cannabis variables using an affect-induction paradigm. Over 700 individuals recruited from Amazon's MTurk participated. After reporting demographics and baseline affect, participants were randomly assigned to either a NA induction or control condition. Follow-up measures assessed post-induction affect and cannabis-related variables. Results revealed that the NA induction task significantly increased NA and decreased positive affect relative to the control condition. Participants assigned to the NA induction reported greater negative cannabis expectancies and more cannabis problems, even after controlling for age and educational attainment. Cannabis use and cannabis problems appeared positively related. Future research should continue to assess for the influence of NA in reporting of cannabis variables. Should subsequent work find differences in reporting of substance use that appear to covary with negative affect, clinicians and researchers alike should be mindful of the implications of potentially biased reporting on assessment, intervention, and research outcomes.

Psychometric Performance of a Substance Use Symptom Checklist to Help Clinicians Assess Substance Use Disorder in Primary Care

Importance

Substance use disorders (SUDs) are underrecognized in primary care, where structured clinical interviews are often infeasible. A brief, standardized substance use symptom checklist could help clinicians assess SUD.

Objective

To evaluate the psychometric properties of the Substance Use Symptom Checklist (hereafter symptom checklist) used in primary care among patients reporting daily cannabis use and/or other drug use as part of population-based screening and assessment.

Design, Setting, and Participants

This cross-sectional study was conducted among adult primary care patients who completed the symptom checklist during routine care between March 1, 2015, and March 1, 2020, at an integrated health care system. Data analysis was conducted from June 1, 2021, to May 1, 2022.

Main Outcomes and Measures

The symptom checklist included 11 items corresponding to SUD criteria in the Diagnostic and Statistical Manual for Mental Disorders (Fifth Edition) (DSM-5). Item response theory (IRT) analyses tested whether the symptom checklist was unidimensional and reflected a continuum of SUD severity and evaluated item characteristics (discrimination and severity). Differential item functioning analyses examined whether the symptom checklist performed similarly across age, sex, race, and ethnicity. Analyses were stratified by cannabis and/or other drug use.

Results

A total of 23 304 screens were included (mean [SD] age, 38.2 [5.6] years; 12 554 [53.9%] male patients; 17 439 [78.8%] White patients; 20 393 [87.5%] non-Hispanic patients). Overall, 16 140 patients reported daily cannabis use only, 4791 patients reported other drug use only, and 2373 patients reported both daily cannabis and other drug use. Among patients with daily cannabis use only, other drug use only, or both daily cannabis and other drug use, 4242 (26.3%), 1446 (30.2%), and 1229 (51.8%), respectively, endorsed 2 or more items on the symptom checklist, consistent with DSM-5 SUD. For all cannabis and drug subsamples, IRT models supported the unidimensionality of the symptom checklist, and all items discriminated between higher and lower levels of SUD severity. Differential item functioning was observed for some items across sociodemographic subgroups but did not result in meaningful change (<1 point difference) in the overall score (0-11).

Conclusions and Relevance

In this cross-sectional study, a symptom checklist, administered to primary care patients who reported daily cannabis and/or other drug use during routine screening, discriminated SUD severity as expected and performed well across subgroups. Findings support the clinical utility of the symptom checklist for standardized and more complete SUD symptom assessment to help clinicians make diagnostic and treatment decisions in primary care.

The Etiologic, Theory-Based, Ontogenetic Hierarchical Framework of Alcohol Use Disorder: A Translational Systematic Review of Reviews

Modern nosologies (e.g., ICD-11, DSM-5) for alcohol use disorder (AUD) and dependence prioritize reliability and clinical presentation over etiology, resulting in a diagnosis that is not always strongly grounded in basic theory and research. Within these nosologies, DSM-5 AUD is treated as a discrete, largely categorical, but graded, phenomenon, which results in additional challenges (e.g., significant phenotypic heterogeneity). Efforts to increase the compatibility between AUD diagnosis and modern conceptualizations of alcohol dependence, which describe it as dimensional and partially overlapping with other psychopathology (e.g., other substance use disorders) will inspire a stronger scientific framework and strengthen AUD's validity. We conducted a systematic review of 144 reviews to integrate addiction constructs and theories into a comprehensive framework with the aim of identifying fundamental mechanisms implicated in AUD. The product of this effort was the Etiologic, Theory-Based, Ontogenetic Hierarchical Framework (ETOH Framework) of AUD mechanisms, which outlines superdomains of cognitive control, reward, as well as negative valence and emotionality, each of which subsume narrower, hierarchically-organized components. We also outline opponent processes and self-awareness as key moderators of AUD mechanisms. In contrast with other frameworks, we recommend an increased conceptual role for negative valence and compulsion in AUD. The ETOH framework serves as a critical step towards conceptualizations of AUD as dimensional and heterogeneous. It has the potential to improve AUD assessment and aid in the development of evidence-based diagnostic measures that focus on key mechanisms in AUD, consequently facilitating treatment matching.

Sleep deficits and cannabis use behaviors: an analysis of shared genetics using linkage disequilibrium score regression and polygenic risk prediction

STUDY OBJECTIVES

Estimate the genetic relationship of cannabis use with sleep deficits and an eveningness chronotype.

METHODS

We used linkage disequilibrium score regression (LDSC) to analyze genetic correlations between sleep deficits and cannabis use behaviors. Secondly, we generated sleep deficit polygenic risk score (PRS) and estimated their ability to predict cannabis use behaviors using linear and logistic regression. Summary statistics came from existing genome-wide association studies of European ancestry that were focused on sleep duration, insomnia, chronotype, lifetime cannabis use, and cannabis use disorder (CUD). A target sample for PRS prediction consisted of high-risk participants and participants from twin/family community-based studies (European ancestry; n = 760, male = 64%; mean age = 26.78 years). Target data consisted of self-reported sleep (sleep duration, feeling tired, and taking naps) and cannabis use behaviors (lifetime ever use, number of lifetime uses, past 180-day use, age of first use, and lifetime CUD symptoms).

RESULTS

Significant genetic correlation between lifetime cannabis use and an eveningness chronotype (rG = 0.24, p < 0.001), as well as between CUD and both short sleep duration (<7 h; rG = 0.23, p = 0.017) and insomnia (rG = 0.20, p = 0.020). Insomnia PRS predicted earlier age of first cannabis use (OR = 0.92, p = 0.036) and increased lifetime CUD symptom count (OR = 1.09, p = 0.012).

CONCLUSION

Cannabis use is genetically associated with both sleep deficits and an eveningness chronotype, suggesting that there are genes that predispose individuals to both cannabis use and sleep deficits.

Which came first: Cannabis use or deficits in impulse control?

Impulse control deficits are often found to co-occur with substance use disorders (SUDs). On the one hand, it is well known that chronic intake of drugs of abuse remodels the brain with significant consequences for a range of cognitive behaviors. On the other hand, individual variation in impulse control may contribute to differences in susceptibility to SUDs. Both of these relationships have been described, thus leading to a "chicken or the egg" debate which remains to be fully resolved. Does impulsivity precede drug use or does it manifest as a function of problematic drug usage? The link between impulsivity and SUDs has been most strongly established for cocaine and alcohol use disorders using both preclinical models and clinical data. Much less is known about the potential link between impulsivity and cannabis use disorder (CUD) or the directionality of this relationship. The initiation of cannabis use occurs most often during adolescence prior to the brain's maturation, which is recognized as a critical period of development. The long-term effects of chronic cannabis use on the brain and behavior have started to be explored. In this review we will summarize these observations, especially as they pertain to the relationship between impulsivity and CUD, from both a psychological and biological perspective. We will discuss impulsivity as a multi-dimensional construct and attempt to reconcile the results obtained across modalities. Finally, we will discuss possible avenues for future research with emerging longitudinal data.

An Item Response Theory Analysis of DSM-5 Heroin Use Disorder in a Clinical Sample of Chinese Adolescents

The study examined the dimensionality and psychometric properties of Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) criteria for heroin use disorder in a clinical sample of Chinese adolescents using item response theory approach. We examined 168 adolescents aged 14.8–17.9 years, who were in treatment for heroin use disorder. A two-parameter logistic item response theory model was conducted to examine the severity and discrimination of DSM-5 criteria for heroin use disorder. Differential item functioning across age and ethnicity was assessed. Results supported the hypothesis that the DSM-5 criteria for heroin use disorder were arrayed an underlying unitary dimension of severity in clinical adolescents. All the items exhibited good discriminatory power in distinguishing between clinical adolescent heroin users. Although three criteria exhibited measurement non-invariance at the item level, the overall DSM-5 heroin use disorder diagnostic criteria set appears to achieve measurement invariance at the scale level.

Deficient Functioning of Frontostriatal Circuits During the Resolution of Cognitive Conflict in Cannabis-Using Youth

OBJECTIVE

Disturbances in self-regulatory control are involved in the initiation and maintenance of addiction, including cannabis use disorder. In adults, long-term cannabis use is associated with disturbances in frontostriatal circuits during tasks that require the engagement of self-regulatory control, including the resolution of cognitive conflict. Understudied are the behavioral and neural correlates of these processes earlier in the course of cannabis use disentangled from effects of long-term use. The present study investigated the functioning of frontostriatal circuits during the resolution of cognitive conflict in cannabis-using youth.

METHOD

Functional magnetic resonance imaging data were acquired from 28 cannabis-using youth and 32 age-matched healthy participants during the performance of a Simon task. General linear modeling was used to compare patterns of brain activation during correct responses to conflict stimuli across groups. Psychophysiologic interaction analyses were used to examine conflict-related frontostriatal connectivity across groups. Associations of frontostriatal activation and connectivity with cannabis use measures were explored.

RESULTS

Decreased conflict-related activity was detected in cannabis-using versus healthy control youth in frontostriatal regions, including the ventromedial prefrontal cortex, striatum, pallidum, and thalamus. Frontostriatal connectivity did not differ across groups, but negative connectivity between the ventromedial prefrontal cortex and striatum was detected in the 2 groups.

CONCLUSION

These findings are consistent with previous reports of cannabis-associated disturbances in frontostriatal circuits in adults and point to the specific influence of cannabis on neurodevelopmental changes in youth. Future studies should examine whether frontostriatal functioning is a reliable marker of cannabis use disorder severity and a potential target for circuit-based interventions.

Concordance between the diagnostic guidelines for alcohol and cannabis use disorders in the draft ICD-11 and other classification systems: analysis of data from the WHO's World Mental Health Surveys

BACKGROUND AND AIMS

The World Health Organization's (WHO's) proposed International Classification of Diseases, 11th edition (ICD-11) includes several major revisions to substance use disorder (SUD) diagnoses. It is essential to ensure the consistency of within-subject diagnostic findings throughout countries, languages and cultures. To date, agreement analyses between different SUD diagnostic systems have largely been based in high-income countries and clinical samples rather than general population samples. We aimed to evaluate the prevalence of, and concordance between diagnoses using the ICD-11, The WHO's ICD 10th edition (ICD-10) and the Diagnostic and Statistical Manual of Mental Disorders, 4th and 5th editions (DSM-IV, DSM-5); the prevalence of disaggregated ICD-10 and ICD-11 symptoms; and variation in clinical features across diagnostic groups.

DESIGN

Cross-sectional household surveys.

SETTING

Representative surveys of the general population in 10 countries (Argentina, Australia, Brazil, Colombia, Iraq, Northern Ireland, Poland, Portugal, Romania and Spain) of the World Mental Health Survey Initiative.

PARTICIPANTS

Questions about SUDs were asked of 12 182 regular alcohol users and 1788 cannabis users.

MEASUREMENTS

Each survey used the World Mental Health Survey Initiative version of the WHO Composite International Diagnostic Interview version 3.0 (WMH-CIDI).

FINDINGS

Among regular alcohol users, prevalence (95% confidence interval) of life-time ICD-11 alcohol harmful use and dependence were 21.6% (20.5-22.6%) and 7.0% (6.4-7.7%), respectively. Among cannabis users, 9.3% (7.4-11.1%) met criteria for ICD-11 harmful use and 3.2% (2.3-4.0%) for dependence. For both substances, all comparisons of ICD-11 with ICD-10 and DSM-IV showed excellent concordance (all κ ≥ 0.9). Concordance between ICD-11 and DSM-5 ranged from good (for SUD and comparisons of dependence and severe SUD) to poor (for comparisons of harmful use and mild SUD). Very low endorsement rates were observed for new ICD-11 feature for harmful use ('harm to others'). Minimal variation in clinical features was observed across diagnostic systems.

CONCLUSIONS

The World Health Organization's proposed International Classification of Diseases, 11th edition (ICD-11) classifications for substance use disorder diagnoses are highly consistent with the ICD 10th edition and the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV). Concordance between ICD-11 and the DSM 5th edition (DSM-5) varies, due largely to low levels of agreement for the ICD harmful use and DSM-5 mild use disorder. Diagnostic validity of self-reported 'harm to others' is questionable.

Marijuana Use by Adolescents and Young Adults with Inflammatory Bowel Disease

OBJECTIVE

To evaluate marijuana use by adolescents and young adults with inflammatory bowel disease (IBD).

STUDY DESIGN

This descriptive cross-sectional study of patients seen between December 2015 through June 2017 at Children's Hospital Colorado for IBD enrolled patients 13-23 years of age, independent of marijuana use status. Information obtained consisted of chart review, electronic and interview self-report, and serum cannabinoid levels. Marijuana ever-users were compared with never-users for clinical characteristics and perceptions of risk with use; users provided information on routes, patterns, motivations, and perceived benefits and problems with use.

RESULTS

Of 99 participants, ever-use was endorsed by 32% (32 of 99) and daily or almost daily use by 9% (9 of 99). Older age was the only characteristic related to endorsing marijuana use. Twenty-nine ever-users completed all questionnaires. After adjusting for age, users were 10.7 times more likely to perceive low risk of harm with regular use (P < .001). At least 1 medical reason for use was endorsed by 57% (17 of 30), most commonly for relief of physical pain (53%, 16 of 30) (2 did not complete all questionnaires). Problems from use were identified by 37% (11 of 30), most commonly craving/strong urge to use. Most common route of use was smoking (83%) followed by edibles (50%), dabbing (40%), and vaping (30%).

CONCLUSIONS

Marijuana use by adolescents and young adults with IBD is common and perceived as beneficial. Guidelines for screening, testing, and counseling of marijuana use should be developed for patients with IBD.

Caffeine use disorder: An item-response theory analysis of proposed DSM-5 criteria

INTRODUCTION

Caffeine is a common psychoactive substance with a documented addictive potential. Caffeine withdrawal has been included in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), but caffeine use disorder (CUD) is considered to be a condition for further study. The aim of the current study is (1) to test the psychometric properties of the Caffeine Use Disorder Questionnaire (CUDQ) by using a confirmatory factor analysis and an item response theory (IRT) approach, (2) to compare IRT models with varying numbers of parameters and models with or without caffeine consumption criteria, and (3) to examine if the total daily caffeine consumption and the use of different caffeinated products can predict the magnitude of CUD symptomatology.

METHODS

A cross-sectional study was conducted on an adult sample (N = 2259). Participants answered several questions regarding their caffeine consumption habits and completed the CUDQ, which incorporates the nine proposed criteria of the DSM-5 as well as one additional item regarding the suffering caused by the symptoms.

RESULTS

Factor analyses demonstrated the unidimensionality of the CUDQ. The suffering criterion had the highest discriminative value at a higher degree of latent trait. The criterion of failure to fulfill obligations and social/interpersonal problems discriminate only at the higher value of CUD latent factor, while endorsement the consumption of more caffeine or longer than intended and craving criteria were discriminative at a lower level of CUD. Total daily caffeine intake was related to a higher level of CUD. Daily coffee, energy drink, and cola intake as dummy variables were associated with the presence of more CUD symptoms, while daily tea consumption as a dummy variable was related to less CUD symptoms. Regular smoking was associated with more CUD symptoms, which was explained by a larger caffeine consumption.

CONCLUSIONS

The IRT approach helped to determine which CUD symptoms indicate more severity and have a greater discriminative value. The level of CUD is influenced by the type and quantity of caffeine consumption.

The generalizability of the structure of substance abuse and antisocial behavioral syndromes: A systematic review

BACKGROUND

Although several authors have suggested that a single externalizing spectrum encompassing both antisocial behavioral syndromes and substance use disorder is to be preferred, this assumption has not been evaluated systematically throughout studies.

PURPOSE

The objective was to establish the generalizability of transdiagnostic models of externalizing disorders across different types of disorders and populations, in regard to the strength of the evidence.

METHOD

We conducted a systematic literature review using combinations of two sets of keywords: 1) "antisocial", "externalizing", "conduct disorder", "disruptive behavior disorder", "substance abuse", "substance-related disorder", "cannabis", "cocaine", "hallucinogen", "alcoholism", "opioid"; 2) "latent structure", "factor analysis", "multivariate analysis".

RESULTS

Models supporting a superordinate factor appeared dominant in a limited set of different populations, on which the majority of the research sample was focused.

CONCLUSIONS

Although the externalizing spectrum model is a promising angle for future research and treatment, extending research on this model in a higher diversity of populations is recommended to enhance the understanding and applicability of the externalizing spectrum model.

Greater Prevalence of Proposed ICD-11 Alcohol and Cannabis Dependence Compared to ICD-10, DSM-IV, and DSM-5 in Treated Adolescents

BACKGROUND

Proposed International Classification of Diseases, 11th edition (ICD-11), criteria for substance use disorder (SUD) radically simplify the algorithm used to diagnose substance dependence. Major differences in case identification across DSM and ICD impact determinations of treatment need and conceptualizations of substance dependence. This study compared the draft algorithm for ICD-11 SUD against DSM-IV, DSM-5, and ICD-10, for alcohol and cannabis.

METHODS

Adolescents (n = 339, ages 14 to 18) admitted to intensive outpatient addictions treatment completed, as part of a research study, a Structured Clinical Interview for DSM SUDs adapted for use with adolescents and which has been used to assess DSM and ICD SUD diagnoses. Analyses examined prevalence across classification systems, diagnostic concordance, and sources of diagnostic disagreement.

RESULTS

Prevalence of any past-year proposed ICD-11 alcohol or cannabis use disorder was significantly lower compared to DSM-IV and DSM-5 (ps < 0.01). However, prevalence of proposed ICD-11 alcohol and cannabis dependence diagnoses was significantly higher compared to DSM-IV, DSM-5, and ICD-10 (ps < 0.01). ICD-11 and DSM-5 SUD diagnoses showed only moderate concordance. For both alcohol and cannabis, youth typically met criteria for an ICD-11 dependence diagnosis by reporting tolerance and much time spent using or recovering from the substance, rather than symptoms indicating impaired control over use.

CONCLUSIONS

The proposed ICD-11 dependence algorithm appears to "overdiagnose" dependence on alcohol and cannabis relative to DSM-IV and ICD-10 dependence, and DSM-5 moderate/severe use disorder, generating potential "false-positive" cases of dependence. Among youth who met criteria for proposed ICD-11 dependence, few reported impaired control over substance use, highlighting ongoing issues in the conceptualization and diagnosis of SUD.

Marijuana Use, Recent Marijuana Initiation, and Progression to Marijuana Use Disorder Among Young Male and Female Adolescents Aged 12-14 Living in US Households

Marijuana initiation during adolescence, and early adolescence in particular, is associated with adverse health consequences. Our study used 2005–2014 data from the annual, cross-sectional National Survey on Drug Use and Health to study the prevalence and correlates of marijuana initiation, use, and marijuana use disorder (MUD; abuse or dependence) among 12- to 14-year olds living in civilian US households (n = 84 954). Examined correlates included age, sex, race/ethnicity, poverty status, metropolitan status, year of survey, depression, tobacco use, alcohol use, and fighting at school. Sex differences in the correlates of lifetime use and past year marijuana initiation were tested via interaction. Lifetime prevalence of marijuana use was 5.5%; 3.2% reported past year initiation. About 1 in 6 (16.8%) past year initiates progressed to MUD within 12 months of first use. Although men had higher prevalence of lifetime use than women, past year initiation did not differ by sex. On examining the sex*race/ethnicity interaction effects, findings determined that non-Hispanic black and Hispanic men had higher prevalence estimates of ever using marijuana and incidence of past year initiation as compared with non-Hispanic white men; these race/ethnicity differences were not found among women. Identifying correlates of initiation and progression to MUD among young adolescents is critical to improve prevention and treatment program targets.

Impaired Decision-Making, Higher Impulsivity, and Drug Severity in Substance Dependence and Pathological Gambling

OBJECTIVES

Substance use disorder is characterized by impaired decision making, impulsivity, and risk taking. Pathological gambling shares many of these characteristics, and having both diagnoses may be associated with greater problems than either diagnosis alone. We investigated whether among substance-dependent individuals, comorbid pathological gambling would be associated with worse decision making, greater impulsivity, risk taking, and drug severity.

METHODS

Ninety-six substance-dependent individuals were recruited from a residential treatment program and divided into 1 of the 2 groups depending on whether they met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria for pathological gambling (SDPG, n = 26) or not (SD, n = 70). Ninety-two controls were recruited from the community. Participants completed a decision-making task (modified Iowa Gambling Task), measures of impulsivity (Barratt Impulsivity Scale and Delay Discounting), and risk taking (Balloon Analog Risk Task). Decision making was analyzed using a computational model. We tested for group differences using analysis of covariance or Kruskal-Wallis and appropriate post-hoc tests.

RESULTS

The groups differed in decision-making parameters (P < 0.001) and self-reported impulsivity (P < 0.001). All post-hoc comparisons were significant on these measures, and indicated stepwise changes in controls, followed by SD, followed by SDPG, with SDPG performing worse on decision making and being more impulsive. Compared with SD, SDPG had greater drug severity (P < 0.001). No group differences were observed in delay discounting or risk taking.

CONCLUSIONS

Compared with individuals with substance dependence without pathological gambling, those with both disorders demonstrated worse decision making and significantly more drug-related symptoms. When evaluating patients with substance dependence, clinicians should consider diagnostic assessments for gambling, as the co-occurrence of both disorders may impact clinical characteristics.

Psychometric modeling of abuse and dependence symptoms across six illicit substances indicates novel dimensions of misuse

AIMS

This study explored the factor structure of DSM III-R/IV symptoms for substance abuse and dependence across six illicit substance categories in a population-based sample of males.

METHOD

DSM III-R/IV drug abuse and dependence symptoms for cannabis, sedatives, stimulants, cocaine, opioids and hallucinogens from 4179 males born 1940-1970 from the population-based Virginia Adult Twin Study of Psychiatric and Substance Use Disorders were analyzed. Confirmatory factor analyses tested specific hypotheses regarding the latent structure of substance misuse for a comprehensive battery of 13 misuse symptoms measured across six illicit substance categories (78 items).

RESULTS

Among the models fit, the latent structure of substance misuse was best represented by a combination of substance-specific factors and misuse symptom-specific factors. We found no support for a general liability factor to illicit substance misuse.

CONCLUSIONS

Results indicate that liability to misuse illicit substances is drug class specific, with little evidence for a general liability factor. Additionally, unique dimensions capturing propensity toward specific misuse symptoms (e.g., tolerance, withdrawal) across substances were identified. While this finding requires independent replication, the possibility of symptom-specific misuse factors, present in multiple substances, raises the prospect of genetic, neurobiological and behavioral predispositions toward distinct, narrowly defined features of drug abuse and dependence.

Natural outcome of cannabis use disorder: a 3-year longitudinal follow-up

AIMS

To assess the prevalence and correlates of remission from cannabis use disorders (CUDs), focusing on the proportion of individuals with CUDs that remit without abstaining from cannabis use.

DESIGN

Three-year longitudinal study.

SETTING

Wave 1 (2001) and wave 2 (2004) of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), a nationally representative sample of US adults aged 18 years and over.

PARTICIPANTS

Our sample included 444 individuals diagnosed with DSM-IV cannabis abuse and/or dependence during the 12 months prior to wave 1 of the NESARC.

MEASUREMENTS

Baseline socio-demographic and clinical correlates were analysed for possible outcomes of CUDs after 3 years: abstinent remission, non-abstinent remission and sustained disorder.

FINDINGS

Approximately two-thirds (67%) of individuals with baseline CUD remitted at follow-up. Approximately 37% of those who remitted were non-abstinent. Remission was associated with Hispanic ethnicity [odds ratio (OR)=2.59; 95% confidence interval (CI)=1.27-4.87], baseline daily or almost daily use of cannabis (OR=1.91; 95% CI=1.15-3.16), baseline use of other drugs (OR=1.63; 95% CI=1.04-2.56) and two or more medical conditions at baseline (OR=8.40; 95% CI=2.67-26.41). Non-abstinent remission was associated with baseline daily or almost daily use of cannabis (OR=1.92; 95% CI=1.05-3.51).

CONCLUSIONS

A substantial level of remission from cannabis use disorders (CUDs), including non-abstinent remission, suggests that the nature of CUDs may be more unstable than reported previously.

Item banks for substance use from the Patient-Reported Outcomes Measurement Information System (PROMIS(®)): Severity of use and positive appeal of use

BACKGROUND

Two item banks for substance use were developed as part of the Patient-Reported Outcomes Measurement Information System (PROMIS(®)): severity of substance use and positive appeal of substance use.

METHODS

Qualitative item analysis (including focus groups, cognitive interviewing, expert review, and item revision) reduced an initial pool of more than 5300 items for substance use to 119 items included in field testing. Items were written in a first-person, past-tense format, with 5 response options reflecting frequency or severity. Both 30-day and 3-month time frames were tested. The calibration sample of 1336 respondents included 875 individuals from the general population (ascertained through an internet panel) and 461 patients from addiction treatment centers participating in the National Drug Abuse Treatment Clinical Trials Network.

RESULTS

Final banks of 37 and 18 items were calibrated for severity of substance use and positive appeal of substance use, respectively, using the two-parameter graded response model from item response theory (IRT). Initial calibrations were similar for the 30-day and 3-month time frames, and final calibrations used data combined across the time frames, making the items applicable with either interval. Seven-item static short forms were also developed from each item bank.

CONCLUSIONS

Test information curves showed that the PROMIS item banks provided substantial information in a broad range of severity, making them suitable for treatment, observational, and epidemiological research in both clinical and community settings.

Commonalities and Differences Across Substance Use Disorders: Phenomenological and Epidemiological Aspects

BACKGROUND

Although psychoactive substances vary in many ways, they have important commonalties, particularly in their ability to lead to an addiction syndrome. The field lacks an updated review of the commonalities and differences in the phenomenology of alcohol, cannabis, tobacco, stimulants, opioids, hallucinogens, sedatives/tranquilizers, and inhalants and their related substance use disorders (SUDs).

METHODS

DSM-IV and DSM-5 SUD diagnostic criteria were reviewed, as was evidence from recent epidemiological and clinical research: psychometric studies (test-retest reliability, latent trait analysis); physiological indicators (tolerance, withdrawal); prevalence and age of onset. Information was incorporated from previous reviews, PubMed and Scopus literature searches, and data from large U.S. national surveys.

RESULTS

Empirical evidence in the form of test-retest reliability and unidimensionality supports use of the same DSM-IV dependence or DSM-5 SUD diagnostic criteria across substances. For most substances, the criteria sets were generally most informative in general population samples at moderate-to-severe levels of SUD. Across substances, 2 criteria (tolerance and use in hazardous situations) were identified as functioning differently in population subgroups. Since substances have different pharmacological effects, withdrawal is assessed using substance-specific symptoms, while tolerance is not; issues remain with the assessment of tolerance. Alcohol, tobacco, and cannabis were consistently identified as the substances with earliest onset of use, highest prevalence of lifetime use, and highest prevalence of lifetime disorder.

CONCLUSIONS

Despite differences between psychoactive substances, the generic DSM criteria set appears equally applicable across substances. Additional studies of tolerance and hazardous use will be useful for future nosologies. Alcohol, cannabis, and tobacco are the substances with the greatest public health impact due to the high prevalence and early onset of their use, and the potential all 3 substances have to lead to addiction.

Genome-Wide Association Study of Behavioral Disinhibition in a Selected Adolescent Sample

Behavioral disinhibition (BD) is a quantitative measure designed to capture the heritable variation encompassing risky and impulsive behaviors. As a result, BD represents an ideal target for discovering genetic loci that predispose individuals to a wide range of antisocial behaviors and substance misuse that together represent a large cost to society as a whole. Published genome-wide association studies (GWAS) have examined specific phenotypes that fall under the umbrella of BD (e.g. alcohol dependence, conduct disorder); however no GWAS has specifically examined the overall BD construct. We conducted a GWAS of BD using a sample of 1,901 adolescents over-selected for characteristics that define high BD, such as substance and antisocial behavior problems, finding no individual locus that surpassed genome-wide significance. Although no single SNP was significantly associated with BD, restricted maximum likelihood analysis estimated that 49.3 % of the variance in BD within the Caucasian sub-sample was accounted for by the genotyped SNPs (p = 0.06). Gene-based tests identified seven genes associated with BD (p ≤ 2.0 × 10(-6)). Although the current study was unable to identify specific SNPs or pathways with replicable effects on BD, the substantial sample variance that could be explained by all genotyped SNPs suggests that larger studies could successfully identify common variants associated with BD.

The influence of age and gender on the likelihood of endorsing cannabis abuse/dependence criteria

INTRODUCTION

Higher prevalence rates of cannabis abuse/dependence and abuse/dependence criteria in 18-24year old versus older cannabis users and in males versus females might reflect true differences in the prevalence of these disorders across age and gender or, alternatively, they could arise from age- and gender-related measurement bias. To understand differences in endorsement across important subgroups, we examined the influence of age and gender simultaneously on the likelihood of endorsement of the various abuse/dependence criteria.

METHOD

The sample consisted of 1603 adult past year cannabis users participating in the National Epidemiological Survey on Alcohol and Related Conditions (NESARC), a U.S. population study (39.6% aged 18-24; 62.1% male). Past year DSM-IV cannabis abuse/dependence criteria and withdrawal were assessed with the AUDADIS-IV. A restricted factor analysis with latent moderated structures was used to detect measurement bias.

RESULTS

Although cannabis abuse and dependence diagnoses and various individual abuse/dependence criteria showed different prevalence rates across younger and older male and female cannabis users, none of the items showed uniform or non-uniform measurement bias with respect to age or gender.

CONCLUSION

The results indicate that, although prevalence rates of cannabis abuse/dependence criteria differ across age and gender, past year abuse/dependence criteria function similarly across these groups. It can thus be concluded that the criteria are applicable to younger and older, as well as male and female, adult cannabis users.

Functioning of cannabis abuse and dependence criteria across two different countries: the United States and The Netherlands

BACKGROUND

Cross-national differences could affect the likelihood of endorsement of DSM cannabis abuse and dependence criteria. The present study examines whether cannabis abuse and dependence criteria function differently across U.S. and Dutch cannabis users.

METHOD

Data on lifetime endorsement of DSM-IV cannabis abuse/dependence criteria were utilized from U.S. cannabis users who participated in the National Epidemiological Survey on Alcohol and Related Conditions (NESARC) and from Dutch cannabis users who participated in the Zuid-Holland study. In total, 1,568 cannabis users participated in the NESARC sample, and 359 cannabis users participated in the Zuid-Holland sample. The DSM-IV cannabis abuse/dependence criteria as well as cannabis withdrawal were determined using face-to-face computer-assisted personal interviews.

RESULTS

Using Restricted Factor Analysis with Latent Moderated Structures, the cannabis abuse/dependence criteria legal problems (β = -0.43), failed quit attempts (β = -1.09), use despite problems (β = -0.32), and withdrawal (β = -0.53) showed measurement bias, and were more likely to be endorsed by U.S. than by Dutch cannabis users. Also, men were more likely than women to endorse the criteria hazardous use (β = -0.27), legal problems (β = -0.49) and tolerance (β = -0.20). Findings on failed quit attempts and withdrawal were replicated in matched subsamples, while results on legal problems (country and gender) were partly replicated.

CONCLUSIONS

Several CUD criteria showed measurement bias across two countries and between males and females. Therefore, differences between countries and gender in prevalence rates of CUD should be regarded with caution.

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.

Genetic relationship between the addiction diagnosis in adults and their childhood measure of addiction liability

Transmissible liability index (TLI), developed employing a high-risk design and item response theory, enables quantification of the latent trait of liability to drug use disorders (DUD) in children. TLI has been shown to have high heritability and predict DUD in young adulthood. This study extends prior research and determines the genetic contribution of DUD liability measured by TLI to adult liability as indexed by DUD diagnosis. The study utilizes data from a twin sample tracked from age 11 to age 25. In addition to confirming TLI's high heritability and predictive validity, it shows that the genetic component of variance in TLI assessed in childhood accounts for over half of the genetic variance in DUD diagnosis and the entire phenotypic relationship between the two liability measures. This validates TLI as an early measure of DUD liability and supports its utility in early-age genetic and other mechanistic studies of DUD.

Does DSM-5 nomenclature for inhalant use disorder improve upon DSM-IV?

Among drug classes, substance use disorder (SUD) consequent to using inhalants (SUD-I) has perhaps the smallest evidence base. This study compared DSM-IV versus DSM-5 nomenclatures, testing whether 4 traditional categories of inhalants (aerosols, gases, nitrites, solvents) are manifestations of a single pathology, obtaining item parameters of SUD-I criteria, and presenting evidence that SUD can result from using nitrites. An urban, Midwestern, community sample of 162 inhalant users was recruited. Participants were 2/3 male, nearly 85% White, and had a mean age of 20.3 years (SD = 2.4 years), spanning the ages of greatest incidence of SUD and slightly older than the primary ages of inhalants use initiation. Analyses consisted of bivariate associations, principle components analysis, and item response theory analysis. Validity was demonstrated for SUD-I consequent to each inhalant type as well as for aggregating all inhalant types into a single drug class. Results supported DSM-5 nomenclature over DSM-IV in multiple ways except that occurrence of diagnostic orphans was not statistically smaller using DSM-5. (PsycINFO Database Record

Gender differences in prevalence of substance use disorders among individuals with lifetime exposure to substances: results from a large representative sample

BACKGROUND AND OBJECTIVES

Research regarding substance use and substance use disorders (SUDs) shows significant gender differences in prevalence of substance use and dependence. Though lifetime exposure to substances is higher among males, previous reports have not regarded gender differences in prevalence of SUDs among individuals formerly exposed to substances. In addition, though substance abuse is particularly important when exploring gender differences, previous reports have largely focused on rates of transition to substance dependence alone. In this study, we explored gender differences in prevalence of SUDs among individuals with lifetime exposure to substances using a single diagnostic category (abuse or dependence).

METHODS

We analyzed 11 different categories of substances: heroin, cocaine, cannabis, nicotine, alcohol, hallucinogens, inhalants, sedatives, tranquilizers, opioids, and amphetamines. Data were derived from the National Epidemiologic Survey on Alcohol and Related Conditions (Wave 1, n = 43,093). The impact of gender on prevalence of SUDs among individuals with lifetime exposure to substances was assessed with odds ratios (ORs) using logistic regressions and adjusted for socio-demographic factors.

RESULTS

Our results show that among individuals with lifetime exposure to substances, males had a significantly higher prevalence of alcohol (OR = 2.95), sedatives (OR = 2.00), cannabis (OR = 1.93), tranquilizers (OR = 1.64), opioids (OR = 1.54), hallucinogens (OR = 1.31), and cocaine (OR = 1.26) use disorders compared with females.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

Using a single broad diagnostic category highlights gender differences in the prevalence of SUDs among individuals with former exposure to substances. Specifically, the significant gender differences found for alcohol, sedatives, and cannabis use disorders may be important for tailoring preventive measures targeted at reducing rates of SUDs among males using these substances.

Concordance between DSM-5 and DSM-IV nicotine, alcohol, and cannabis use disorder diagnoses among pediatric patients

BACKGROUND

The recently published Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5) includes several major revisions to substance use diagnoses. Studies have evaluated the impact of these changes among adult samples but research with adolescent samples is lacking.

METHODS

525 adolescents (93% African American) awaiting primary care appointments in Baltimore, Maryland were recruited for a study evaluating a substance use screening instrument. Participants were assessed for DSM-5 nicotine, alcohol, and cannabis use disorder, DSM-IV alcohol and cannabis abuse, and DSM-IV dependence for all three substances during the past year using the modified Composite International Diagnostic Interview-2, Substance Abuse Module. Contingency tables examining DSM-5 vs. DSM-IV joint frequency distributions were examined for each substance.

RESULTS

Diagnoses were more prevalent using DSM-5 criteria compared with DSM-IV for nicotine (4.0% vs. 2.7%), alcohol (4.6% vs. 3.8%), and cannabis (10.7% vs. 8.2%). Cohen's κ, Somers' d, and Cramer's V ranged from 0.70 to 0.99 for all three substances. Of the adolescents categorized as "diagnostic orphans" under DSM-IV, 7/16 (43.8%), 9/29 (31.0%), and 13/36 (36.1%) met criteria for DSM-5 disorder for nicotine, alcohol, and cannabis, respectively. Additionally, 5/17 (29.4%) and 1/21 (4.8%) adolescents who met criteria for DSM-IV abuse did not meet criteria for a DSM-5 diagnosis for alcohol and cannabis, respectively.

CONCLUSIONS

Categorizing adolescents using DSM-5 criteria may result in diagnostic net widening-particularly for cannabis use disorders-by capturing adolescents who were considered diagnostic orphans using DSM-IV criteria. Future research examining the validity of DSM-5 substance use disorders with larger and more diverse adolescent samples is needed.

Comparing factor, class, and mixture models of cannabis initiation and DSM cannabis use disorder criteria, including craving, in the Brisbane longitudinal twin study

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.

DSM-5 cannabis use disorder: a phenotypic and genomic perspective

BACKGROUND

We explore the factor structure of DSM-5 cannabis use disorders, examine its prevalence across European- and African-American respondents as well as its genetic underpinnings, utilizing data from a genome-wide study of single nucleotide polymorphisms (SNPs). We also estimate the heritability of DSM-5 cannabis use disorders explained by these common SNPs.

METHODS

Data on 3053 subjects reporting a lifetime history of cannabis use were utilized. Exploratory and confirmatory factor analyses were conducted to create a factor score, which was used in a genome-wide association analysis. p-values from the single SNP analysis were examined for evidence of gene-based association. The aggregate effect of all SNPs was also estimated using Genome-Wide Complex Traits Analysis.

RESULTS

The unidimensionality of DSM-5 cannabis use disorder criteria was demonstrated. Comparing DSM-IV to DSM-5, a decrease in prevalence of cannabis use disorders was only noted in European-American respondents and was exceedingly modest. For the DSM-5 cannabis use disorders factor score, no SNP surpassed the genome-wide significance testing threshold. However, in the European-American subsample, gene-based association testing resulted in significant associations in 3 genes (C17orf58, BPTF and PPM1D) on chromosome 17q24. In aggregate, 21% of the variance in DSM-5 cannabis use disorders was explained by the genome-wide SNPs; however, this estimate was not statistically significant.

CONCLUSIONS

DSM-5 cannabis use disorder represents a unidimensional construct, the prevalence of which is only modestly elevated above the DSM-IV version. Considerably larger sample sizes will be required to identify individual SNPs associated with cannabis use disorders and unequivocally establish its polygenic underpinnings.

C-reactive protein and substance use disorders in adolescence and early adulthood: a prospective analysis

BACKGROUND

Dysregulated immune function and elevated inflammation markers are seen in adults with chronic diseases, including some psychiatric disorders, but evidence on inflammation in the case of drug abuse is conflicting.

OBJECTIVE

To test the concurrent and predictive relations between C-reactive protein (CRP) and use and abuse of alcohol, nicotine and cannabis in a longitudinal, population sample of adolescents and young adults, at the period of highest increase in drug use.

METHODS

Data from the prospective population-based Great Smoky Mountains Study (N=1420) were used, covering children in the community assessed at ages 9-16, 19, and 21. Structured interviews were used to assess substance abuse symptoms and DSM-IV substance use disorders. Bloodspots were collected at each assessment and assayed for CRP.

RESULTS

CRP levels were higher in the presence of nicotine, alcohol, and cannabis use and nicotine dependence. In prospective analyses, higher CRP levels predicted cannabis use and nicotine dependence, and nicotine use predicted higher CRP levels, once covariates were included in the models. Significant covariates were age, race (American Indian), and obesity.

CONCLUSIONS

The inter-relationship of CRP and substance abuse has implications for the later health risks associated with early drug and alcohol use and abuse.

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.

Motivation for change and barriers to treatment among young cannabis users

BACKGROUND/AIMS

Despite cannabis use among adolescents has shown to be related to psychosocial and mental health problems, the demand from adolescents for professional help is very low, and determinants of motivation for change among nonclinical populations remain unknown. The purpose of this study was to assess motivation for change among young cannabis users and to identify determinants of intention to change and self-change, as well as perceived barriers to seeking professional help.

METHODS

261 cannabis users aged 16-21 participated in a computerized survey in Spain.

RESULTS

Data from this cross-sectional study indicated that few users intend to stop taking the drug. Determining factors of intention to change were the following: having more drug-related problems, paranoid symptomatology and greater concern about the consequences of use. Self-change was facilitated by lower use of cannabis, and could be hindered by tobacco smoking and cannabis dependence. Lack of awareness of the problems and the desire to solve one's problems alone constitute the main barriers to seeking professional help.

CONCLUSIONS

Adolescent cannabis users show low motivation for change though experiencing more problems associated with its use emerges as a determinant of increased motivation. Several barriers impede this motivation from turning into treatment demand.

Subjective effects for alcohol, tobacco, and marijuana association with cross-drug outcomes

METHODS

The cross-drug relationship of subjective experiences between alcohol, tobacco, and marijuana and problem drug use behaviors were examined. Data were drawn from 3853 individuals between the ages of 11 and 30 years of age participating in the Colorado Center on Antisocial Drug Dependence [CADD]. Subjective experiences were assessed using a 13-item questionnaire that included positive and negative responses for alcohol, tobacco, and marijuana. Lifetime abuse and dependence on these three drugs was assessed using the Composite International Diagnostic Interview, Substance Abuse Module [CIDI-SAM].

RESULTS

Positive and negative subjective experience scales were similar for alcohol, tobacco, and marijuana, although the hierarchical ordering of items differed by drug. Subjective experience scales for each of the three drugs examined correlated significantly, with the strongest relationship being for alcohol and marijuana experiences. Significant associations were identified between how a person experienced a drug and abuse and dependence status for the same or different drug.

CONCLUSION

Cross-drug relationships provide evidence for a common liability or sensitivity towards responding in a similar manner to drugs of abuse within and across different pharmacological classes.

Greater prevalence of proposed DSM-5 nicotine use disorder compared to DSM-IV nicotine dependence in treated adolescents and young adults

AIMS

Compared to DSM-IV nicotine dependence, proposed DSM-5 nicotine use disorder (NUD) would lower the threshold from three to two symptoms, and increase the number of criteria used for diagnosis from seven to 11. The impact of the proposed changes on nicotine disorder prevalence and the concurrent validity of diagnostic criteria were examined.

DESIGN

Cross-sectional survey to compare DSM-IV and proposed DSM-5 algorithms.

SETTING AND PARTICIPANTS

Adolescent (n = 179) and young adult (n = 292) past-year cigarette users recruited from addictions treatment.

MEASUREMENTS

Semi-structured clinical interview to evaluate DSM-IV nicotine dependence, and 10 of the 11 proposed DSM-5 NUD criteria; 30-day time-line follow-back; and the Fagerström Test for Nicotine Dependence (FTND).

FINDINGS

Prevalence of proposed DSM-5 NUD (two-symptom threshold) was much higher (adolescents: 68.7%, young adults: 86.0%) than DSM-IV nicotine dependence (33.0% and 59.6%, respectively), although prevalence of DSM-5 severe NUD (four-symptom threshold) was similar to DSM-IV nicotine dependence. Concurrent validity analyses in both samples indicated consistent support for DSM-5 severe NUD diagnosis (four symptoms) but not for the moderate NUD (two symptoms) diagnosis, which had modest relations with only FTND score. IRT analyses indicated strong support for the new craving item, but not for the proposed interpersonal problems and hazardous use items.

CONCLUSIONS

The proposed DSM-5 nicotine use disorder criteria have substantial limitations when applied to adolescents and young adults, and appear to have low concurrent validity.

Analyses related to the development of DSM-5 criteria for substance use related disorders: 2. Proposed DSM-5 criteria for alcohol, cannabis, cocaine and heroin disorders in 663 substance abuse patients

BACKGROUND

A number of changes have been proposed and investigated in the criteria for substance use disorders in DSM-5. However, although clinical utility of DSM-5 is a high priority, relatively little of the empirical evidence supporting the changes was obtained from samples of substance abuse patients.

METHODS

Proposed changes were examined in 663 patients in treatment for substance use disorders, evaluated by experienced clinicians using the Psychiatric Research Interview for Substance and Mental Disorders (PRISM). Factor and item response theory analysis was used to investigate the dimensionality and psychometric properties of alcohol, cannabis, cocaine and heroin abuse and dependence criteria, and craving.

RESULTS

The seven dependence criteria, three of the abuse criteria (hazardous use; social/interpersonal problems related to use; neglect of roles to use), and craving form a unidimensional latent trait for alcohol, cannabis, cocaine and heroin. Craving did not add significantly to the total information offered by the dependence criteria, but adding the three abuse criteria and craving together did significantly increase total information for the criteria sets associated with alcohol, cannabis and heroin.

CONCLUSION

Among adult patients in treatment for substance disorders, the alcohol, cannabis, cocaine and heroin criteria for dependence, abuse (with the exception of legal problems), and craving measure a single underlying dimension. Results support the proposal to combine abuse and dependence into a single diagnosis in the DSM-5, omitting legal problems. Mixed support was provided for the addition of craving as a new criterion, warranting future studies of this important construct in substance use disorders.

Are the symptoms of cannabis use disorder best accounted for by dimensional, categorical, or factor mixture models? A comparison of male and female young adults

Despite the consensus that criteria for cannabis abuse and dependence and symptoms of withdrawal are best explained by a single latent liability, it remains unknown whether alternative models provide a better explanation of these criteria. A series of latent factor, latent class, and hybrid factor mixture models were fitted to data from 872 recent cannabis users from the Minnesota Twin Family Study who completed Diagnostic and Statistical Manual of Mental Disorders (3rd ed., revised, and 4th ed.) diagnostic criteria for cannabis abuse, dependence, and symptoms of withdrawal. Despite theoretical appeal, results did not support latent class or factor mixture modeling. Instead, symptoms of abuse, dependence, and withdrawal were better summarized by a single latent factor Cannabis Use Disorder (CUD) for male and female young adults. An almost 2-fold sex difference in item endorsement was best explained by a single mean difference on the CUD factor, indicating that young men have a greater latent liability toward expressing CUD.

Psychometric modeling of cannabis initiation and use and the symptoms of cannabis abuse, dependence and withdrawal in a sample of male and female twins

BACKGROUND

Despite an emerging consensus that the DSM-IV diagnostic criteria for cannabis abuse and dependence are best represented by a single underlying liability, it remains unknown if latent class or hybrid models can better explain the data.

METHOD

Using structured interviews, 7316 adult male and female twins provided complete data on DSM-IV symptoms of cannabis abuse and dependence. Our aim was to derive a parsimonious, best-fitting cannabis use disorder (CUD) phenotype based on DSM-III-R/IV criteria by comparing an array of psychometric models (latent factor analysis, latent class analysis and factor mixture modeling) using full information maximum likelihood ordinal data methods in Mx.

RESULTS

We found little evidence to support population heterogeneity since neither latent class nor hybrid factor mixture models provided a consistently good fit to the data. When conditioned on initiation and cannabis use, the endorsement patterns of the abuse, dependence and withdrawal criteria were best explained by two latent factors for males and females. The first was a general CUD factor for which genetic effects explained 53-54% of the variance. A less interpretable second factor included a mix of cross-loading dependence and withdrawal symptoms.

CONCLUSIONS

This is the first study to compare competing measurement models to derive an empirically determined CUD phenotype. Commensurate with proposed changes to substance use disorders in the DSM-V, our results support an emerging consensus that a single CUD latent factor can more optimally assess the risk or liability underpinning correlated measures of use, abuse, dependence and withdrawal criterion.

The validity of DSM-IV cannabis abuse and dependence criteria in adolescents and the value of additional cannabis use indicators

AIMS

This study assessed the validity of DSM-IV cannabis abuse and dependence criteria in an adolescent general population sample and evaluated the usefulness of additional cannabis use indicators.

DESIGN AND SETTING

Data came from the 2008 Survey on Health and Consumption during the Day of Defense Preparation (ESCAPAD), a cross-sectional self-administered survey conducted in France.

PARTICIPANTS

The analytical sample comprised 3641 adolescents aged 17-19 years who reported cannabis use in the past 12 months.

MEASUREMENTS

To assess DSM-IV criteria of cannabis abuse and dependence, the Munich Composite International Diagnostic Interview (M-CIDI) was used. As additional cannabis use indicators, daily use, use when alone and use before midday were assessed. Confirmatory factor analyses and two-parameter logistic item response theory (IRT) models were run. Differential item functioning was assessed using the IRT log-likelihood ratio approach.

RESULTS

A one-factor model comprising both abuse and dependence criteria showed the best fit to the data. Abuse item legal problems showed the greatest severity, whereas dependence items larger/longer and tolerance were found least severe. Discriminatory power was lowest for impaired control and legal problems. Additional cannabis use indicators increased the precision of the overall DSM-IV criterion set. Gender-based differential item functioning was observed for items tolerance, withdrawal and use before midday.

CONCLUSION

The current DSM conceptualization with two distinct and graded diagnostic classes has limited validity among adolescents. In forthcoming revisions of the classification system, several existing criteria should be revised or dropped, new indicators of substance use disorders should be included and gender should be considered.

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.

Common and drug-specific genetic influences on subjective effects to alcohol, tobacco and marijuana use

AIM

To examine variation in positive and negative subjective effects to alcohol, tobacco and marijuana and covariation between these three drugs and each effect.

DESIGN

Retrospective self-reports of subjective effects were collected to estimate the genetic and environmental influences and the extent of their specificity across three drugs.

PARTICIPANTS

Data were drawn from 1299 adolescent and young adult same- and opposite sex twin- and sibling-pairs participating in the Colorado Center for Antisocial Drug Dependence (CADD).

SETTING

A large, collaborative, longitudinal study of substance use and antisocial behavior in community and clinical adolescents.

MEASUREMENT

  Subjective effects were assessed using a 13-item questionnaire that included positive and negative responses to alcohol, tobacco and marijuana.

FINDINGS

Heritable influences contributed moderately (additive genetic effects 16-56%) to positive and negative subjective effects to all three drugs and did not differ for males and females. Genetic and environmental contributions to positive and negative subjective effects are largely non-overlapping for tobacco and marijuana. Multivariate genetic modeling indicated that subjective effects to alcohol, tobacco and marijuana share a common, heritable etiology and that drug-specific genetic influences were an important contributor to individual differences in drug response.

CONCLUSIONS

  Results from our genetic analyses suggest that subjective effects to these commonly used and misused drugs are heritable and that the genetic and environmental influences on effects to one drug also influence subjective effects to other drugs.

Adolescent cannabis use and psychosis: epidemiology and neurodevelopmental models

Cannabis is one of the most widely used illicit drugs among adolescents, and most users first experiment with it in adolescence. Adolescence is a critical phase for brain development, characterized by neuronal maturation and rearrangement processes, such as myelination, synaptic pruning and dendritic plasticity. The endocannabinoid system plays an important role in fundamental brain developmental processes such as neuronal cell proliferation, migration and differentiation. Therefore changes in endocannabinoid activity during this specific developmental phase, induced by the psychoactive component of marijuana, Delta(9)-tetrahydrocannabinol, might lead to subtle but lasting neurobiological changes that can affect brain functions and behaviour. In this review, we outline recent research into the endocannabinoid system focusing on the relationships between adolescent exposure to cannabinoids and increased risk for certain neuropsychiatric diseases such as schizophrenia, as highlighted by both human and animal studies. Particular emphasis will be given to the possible mechanisms by which adolescent cannabis consumption could render a person more susceptible to developing psychoses such as schizophrenia.

Revising the Cannabis Use Disorders Identification Test (CUDIT) by means of Item Response Theory

Cannabis use among adolescents and young adults has become a major public health challenge. Several European countries are currently developing short screening instruments to identify 'problematic' forms of cannabis use in general population surveys. One such instrument is the Cannabis Use Disorders Identification Test (CUDIT), a 10-item questionnaire based on the Alcohol Use Disorders Identification Test. Previous research found that some CUDIT items did not perform well psychometrically. In the interests of improving the psychometric properties of the CUDIT, this study replaces the poorly performing items with new items that specifically address cannabis use. Analyses are based on a sub-sample of 558 recent cannabis users from a representative population sample of 5722 individuals (aged 13-32) who were surveyed in the 2007 Swiss Cannabis Monitoring Study. Four new items were added to the original CUDIT. Psychometric properties of all 14 items, as well as the dimensionality of the supplemented CUDIT were then examined using Item Response Theory. Results indicate the unidimensionality of CUDIT and an improvement in its psychometric performance when three original items (usual hours being stoned; injuries; guilt) are replaced by new ones (motives for using cannabis; missing out leisure time activities; difficulties at work/school). However, improvements were limited to cannabis users with a high problem score. For epidemiological purposes, any further revision of CUDIT should therefore include a greater number of 'easier' items.

ADHD in a representative sample of the Brazilian population: estimated prevalence and comparative adequacy of criteria between adolescents and adults according to the item response theory

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is a clinically significant disorder in adulthood, but current diagnostic criteria and instruments do not seem to adequately capture the complexity of the disorder in this developmental phase. Accordingly, there are limited data on the proportion of adults affected by the disorder, specially in developing countries.

METHOD

We assessed a representative household sample of the Brazilian population for ADHD with the Adult ADHD Self-report Scale (ASRS) Screener, and evaluated the instrument according to the Rasch model of item response theory.

RESULTS

The sample was comprised by 3007 individuals, and the overal prevalence of positive screeners for ADHD was 5.8% [95% confidence interval (CI), 4.8-7.0]. Rasch analyses revealed the misfitt of the overall sample to expectations of the model. The evaluation of the sample stratified by age revealed that data for adolescents showed a signficant fittnes to the model expectations, while items completed by adults were not adequated.

CONCLUSIONS

The lack of fitness to the model for adult respondents challenges the possibility of a linear transformation of the ordinal data into interval measures and the utilization of parametric analyses of data. This result suggests that diagnostic criteria and instruments for adult ADHD must take into account a developmental perspective. Moreover, it calls for further evaluation of currently employed research methods in light of modern theories of psychometrics.

Subjective effects to marijuana associated with marijuana use in community and clinical subjects

INTRODUCTION

Marijuana is the most commonly used illicit drug among adolescents. Marijuana use induces both psychological and physiological responses, which can be interpreted by an individual in a variety of ways (i.e. subjective effects). We have examined subjective effects in adolescent, young adult community, and clinical populations to determine how patterns of use may be predicted by an individual's subjective experiences with the drug.

METHOD

Participants were community and clinical sample subjects drawn from the Colorado Center of Antisocial Drug Dependence (CADD) and a sample of adjudicated youth from the Denver metropolitan area (aged 11-30). They were evaluated with the Composite International Diagnostic Interview-Substance Abuse Module (CIDI-SAM) and the Lyons battery for subjective effects. Scales for subjective effects were created using Mokken scale analysis. Multivariate linear and logistic regression was used to examine associations between the subjective scales and marijuana outcomes.

RESULTS

Mokken scaling revealed two subjective effects scales, positive and negative. Both scales were significantly positively associated with marijuana abuse or dependence in both the community and clinical sample and regular use in the community sample. The negative scale was negatively associated with past six-month use in the community sample (p<0.05) and clinical sample, after controlling for age and gender effects.

CONCLUSIONS

These findings suggest that diverse subjective experiences with marijuana can be ordered hierarchically and that the resulting short scales can be used in either clinical or community settings. Further, they suggest that the potential for marijuana use problems is related to the type of subjective experience from marijuana exposure.

"Youthful epidemic" or diagnostic bias? Differential item functioning of DSM-IV cannabis use criteria in an Australian general population survey

BACKGROUND

Prevalence rates of cannabis abuse and dependence are higher for younger adults when compared with older adults. It is necessary to examine the performance of criteria across age groups to establish whether these differences in prevalence rates are a result of diagnostic bias. The current study aims to investigate whether there is any age-related differential item functioning in the DSM-IV diagnostic criteria for cannabis use disorders using an item response theory approach.

METHOD

The sample consisted of 10,641 participants in a population-based survey of Australian adults aged 18 years and older. DSM-IV cannabis use disorders were assessed in all respondents who had used cannabis more than five times in the previous twelve months (n=722). Age-based differential item functioning was assessed in each of the DSM-IV criteria for cannabis use disorders.

RESULTS

Age-based differential item functioning was only detected in the Hazard criterion of the DSM-IV cannabis use disorders. The Hazard criterion was found to be more discriminating for those aged 18-24 when compared with those aged 25 and over.

CONCLUSIONS

The DSM-IV criteria for cannabis use disorders appear to function similarly across age groups. Differential item functioning was only detected in the alpha parameter for the Hazard criterion. These results are discussed with regard to implications for future editions of the DSM system.

An item response theory analysis of DSM-IV criteria for hallucinogen abuse and dependence in adolescents

AIM

This study applied both item response theory (IRT) and multiple indicators-multiple causes (MIMIC) methods to evaluate item-level psychometric properties of diagnostic questions for hallucinogen use disorders (HUDs), differential item functioning (DIF), and predictors of latent HUD.

METHODS

Data were drawn from 2004-2006 National Surveys on Drug Use and Health. Analyses were based on 1548 past-year hallucinogen users aged 12-17 years. Substance use and symptoms were assessed by audio computer-assisted self-interviewing methods.

RESULTS

Abuse and dependence criteria empirically were arrayed along a single continuum of severity. All abuse criteria indicated middle-to-high severity on the IRT-defined HUD continuum, while dependence criteria captured a wider range from the lowest (tolerance and time spent) to the highest (taking larger amounts and inability to cut down) severity levels. There was indication of DIF by hallucinogen users' age, gender, race/ethnicity, and ecstasy use status. Adjusting for DIF, ecstasy users (vs. non-ecstasy hallucinogen users), females (vs. males), and whites (vs. Hispanics) exhibited increased odds of HUD.

CONCLUSIONS

Symptoms of hallucinogen abuse and dependence empirically do not reflect two discrete conditions in adolescents. Trends and problems related to hallucinogen use among girls and whites should be examined further to inform the designs of effective gender-appropriate and culturally sensitive prevention programs.