A genome-wide association study of cocaine use disorder accounting for phenotypic heterogeneity and gene­environment interaction

Background: Phenotypic heterogeneity and complicated gene­environment interplay in etiology are among the primary factors that hinder the identification of genetic variants associated with cocaine use disorder. Methods: To detect novel genetic variants associated with cocaine use disorder, we derived disease traits with reduced phenotypic heterogeneity using cluster analysis of a study sample (n = 9965). We then used these traits in genome-wide association tests, performed separately for 2070 African Americans and 1570 European Americans, using a new mixed model that accounted for the moderating effects of 5 childhood environmental factors. We used an independent sample (918 African Americans, 1382 European Americans) for replication. Results: The cluster analysis yielded 5 cocaine use disorder subtypes, of which subtypes 4 (n = 3258) and 5 (n = 1916) comprised heavy cocaine users, had high heritability estimates (h2 = 0.66 and 0.64, respectively) and were used in association tests. Seven of the 13 identified genetic loci in the discovery phase were available in the replication sample. In African Americans, rs114492924 (discovery p = 1.23 × E−8), a single nucleotide polymorphism in LINC01411, was replicated in the replication sample (p = 3.63 × E−3). In a meta-analysis that combined the discovery and replication results, 3 loci in African Americans were significant genome-wide: rs10188036 in TRAK2 (p = 2.95 × E−8), del-1:15511771 in TMEM51 (p = 9.11 × E−10) and rs149843442 near LPHN2 (p = 3.50 × E−8). Limitations: Lack of data prevented us from replicating 6 of the 13 identified loci. Conclusion: Our results demonstrate the importance of considering phenotypic heterogeneity and gene­environment interplay in detecting genetic variations that contribute to cocaine use disorder, because new genetic loci have been identified using our novel analytic method.

Successful classification of cocaine dependence using brain imaging: a generalizable machine learning approach.

BACKGROUND: Neuroimaging studies have yielded significant advances in the understanding of neural processes relevant to the development and persistence of addiction. However, these advances have not explored extensively for diagnostic accuracy in human subjects. The aim of this study was to develop a statistical approach, using a machine learning framework, to correctly classify brain images of cocaine-dependent participants and healthy controls. In this study, a framework suitable for educing potential brain regions that differed between the two groups was developed and implemented. Single Photon Emission Computerized Tomography (SPECT) images obtained during rest or a saline infusion in three cohorts of 2-4 week abstinent cocaine-dependent participants (n = 93) and healthy controls (n = 69) were used to develop a classification model. An information theoretic-based feature selection algorithm was first conducted to reduce the number of voxels. A density-based clustering algorithm was then used to form spatially connected voxel clouds in three-dimensional space. A statistical classifier, Support Vectors Machine (SVM), was then used for participant classification. Statistically insignificant voxels of spatially connected brain regions were removed iteratively and classification accuracy was reported through the iterations. RESULTS: The voxel-based analysis identified 1,500 spatially connected voxels in 30 distinct clusters after a grid search in SVM parameters. Participants were successfully classified with 0.88 and 0.89 F-measure accuracies in 10-fold cross validation (10xCV) and leave-one-out (LOO) approaches, respectively. Sensitivity and specificity were 0.90 and 0.89 for LOO; 0.83 and 0.83 for 10xCV. Many of the 30 selected clusters are highly relevant to the addictive process, including regions relevant to cognitive control, default mode network related self-referential thought, behavioral inhibition, and contextual memories. Relative hyperactivity and hypoactivity of regional cerebral blood flow in brain regions in cocaine-dependent participants are presented with corresponding level of significance. CONCLUSIONS: The SVM-based approach successfully classified cocaine-dependent and healthy control participants using voxels selected with information theoretic-based and statistical methods from participants' SPECT data. The regions found in this study align with brain regions reported in the literature. These findings support the future use of brain imaging and SVM-based classifier in the diagnosis of substance use disorders and furthering an understanding of their underlying pathology.

The value of impulsivity to define subgroups of addicted individuals differing in personality dysfunction, craving, psychosocial adjustment, and wellbeing: a latent class analysis.

High impulsivity is common to substance and gambling addictions. Despite these commonalities, there is still substantial heterogeneity on impulsivity levels within these diagnostic groups, and variations in impulsive levels predict higher severity of symptoms and poorer outcomes. We addressed the question of whether impulsivity scores can yield empirically driven subgroups of addicted individuals that will exhibit different clinical presentations and outcomes. We applied latent class analysis (LCA) to trait (UPPS-P impulsive behavior scale) and cognitive impulsivity (Stroop and d2 tests) scores in three predominantly male addiction diagnostic groups: Cocaine with Personality Disorders, Cocaine Non-comorbid, and Gambling and analyzed the usefulness of the resulting subgroups to differentiate personality beliefs and relevant outcomes: Craving, psychosocial adjustment, and quality of life. In accordance with impulsivity scores, the three addiction diagnostic groups are best represented as two separate classes: Class 1 characterized by greater trait impulsivity and poorer cognitive impulsivity performance and Class 2 characterized by lower trait impulsivity and better cognitive impulsivity performance. The two empirically derived classes showed significant differences on personality features and outcome variables (Class 1 exhibited greater personality dysfunction and worse clinical outcomes), whereas conventional diagnostic groups showed non-significant differences on most of these measures. Trait and cognitive impulsivity scores differentiate subgroups of addicted individuals with more versus less severe personality features and clinical outcomes.

Cocaine use disorder prevalence: From current DSM-IV to proposed DSM-5 diagnostic criteria with both a two and three severity level classification system.

This article presents a secondary analysis from a study investigating the compatibility of the current DSM-IV and previously proposed DSM-5 cocaine use disorder (CUD) criteria (S. L. Proctor, A. M. Kopak, & N. G. Hoffmann, 2012, Compatibility of current DSM-IV and proposed DSM-5 diagnostic criteria for cocaine use disorders. Addictive Behaviors, 37, 722-728). The current analyses examined the compatibility of the current DSM-IV and two sets of proposed DSM-5 diagnostic criteria for CUDs among adult male inmates (N = 6,871) recently admitted to the Minnesota Department of Corrections state prison system from 2000-2003. Initially proposed DSM-5 criteria (DSM-5.0) featured only two diagnostic designations (i.e., moderate and severe). A subsequent revision (DSM-5.1) included the addition of a mild designation and required a greater number of positive findings for the severe designation. A computer-prompted structured diagnostic interview was administered to all inmates as part of routine clinical assessments. The past 12-month prevalence of DSM-IV CUDs was 12.70% (Abuse, 3.78%, Dependence, 8.92%), while 10.98% met past 12-month DSM-5.1 criteria for a CUD (Mild [MiCUD], 1.72%; Moderate [MCUD], 1.12%; and Severe [SCUD], 8.14%). The vast majority of those with no diagnosis (99.6%) continued to have no diagnosis, and most of those with a dependence diagnosis (91.2%) met SCUD criteria of the proposed DSM-5.1. Most of the variation in DSM-5.1 diagnostic classifications was accounted for by those with a current abuse diagnosis. DSM-5.0 MCUD cases were most affected when DSM-5.1 criteria were applied. The proposed diagnostic changes might translate to reduced access to treatment for those individuals evincing symptoms consistent with DSM-IV cocaine abuse.

[Subtypes of cocaine addicts with and without associated problematic alcohol use: towards a neuropsychology of personality applied to clinical practice]. / Subtipos de adictos a la cocaína con y sin consumo problemático de alcohol asociado: hacia una neuropsicología de la personalidad aplicada a la clínica.

It is important to know which personality factors are associated with addiction so to distinguish addicts that require specialized treatment from those who do not, and to identify those addicts who achieve abstinence from those who continue their substance use despite the negative consequences. Cloninger's model includes biological and psychosocial variables that can be characterized in neuropsychological terms. Two samples were analyzed: individuals who had begun cocaine addiction treatment (n=183) and a non-clinical population sample (n = 183), matched for sex, age and educational level. Alcohol abuse/dependence was monitored as an independent variable. Significant differences and large effect size were found between addicts and non-clinical population in Novelty Seeking and Self-Directedness, and to a lesser extent, in Harm Avoidance. These differences increase when problematic use of alcohol is added. According to the profile of traits, clusters of addicts were established and differences were obtained in variables such as functional/dysfunctional impulsivity, dysexecutive symptoms and perceived stress. Six clusters were identified, some of minor severity, the most severely problematic clusters being characterized by higher levels of dysfunctional impulsivity, more dysexecutive symptoms and higher levels of perceived stress. Self-Directedness seems to reflect the deficit of prefrontal systems in the regulation of behavior, as well as in emotion and impulse control. It is proposed that evaluation of the personality is more useful than the mere assessment of symptoms for classifying addicts, determining their needs and designing a therapeutic itinerary.

Latent classes of heroin and cocaine users predict unique HIV/HCV risk factors.

BACKGROUND: Patterns of heroin and cocaine use vary and may be associated with unique risk factors for bloodborne infections. METHODS: Latent class analysis identified sub-populations of 552 heroin and cocaine users in Baltimore, Maryland. Using latent class regression, these classes were analyzed for associations with demographic characteristics, risky behaviors, Hepatitis C, and HIV. RESULTS: Three classes were found: Crack/Nasal-Heroin users (43.5%), Polysubstance users (34.8%), and Heroin Injectors (21.8%). Compared to Polysubstance users, Crack/Nasal-Heroin users were almost 7 times more likely to identify as Black (OR=6.97, 95% CI=4.35-11.2). Sharing needles was over 2.5 times more likely among Polysubstance users than among Heroin Injectors (OR=2.66, 95% CI=1.49-4.75). Crack/Nasal-Heroin users were 2.5 times more likely than Polysubstance users to exchange drugs for sex (OR=2.50, 95% CI=1.22-5.13). Crack/Nasal-Heroin users were less likely than Heroin Injectors to have Hepatitis C (OR=0.10, 95% CI=0.06-0.18), but no significant differences were found for HIV. CONCLUSIONS: Subpopulations of cocaine and heroin users differed in demographic classifications, HIV-risk behaviors, and Hepatitis C infection. All subpopulations included substantial numbers of HIV-positive individuals. Findings provide further evidence that non-injection drug users face significant infectious disease risk.

[Abstinence from cocaine after long-term addiction]. / Abstinence à la cocaïne après un parcours de dépendance.

BACKGROUND: Experimental data strongly suggest that in animal and probably in man, noradrenergic and serotoninergic become uncoupled during repeated consumption of drugs of abuse, strongly suggesting that different drugs share common mechanisms for drug-dependence. Using cocaine-dependence as model of strong addiction we speculate that careful analysis of psychic adjustments in patients who experience prolonged abstinence could be a useful tool for patient's care. AIM: The aim of this retrospective study was first to establish similarities in patients' histories concerning modes of entrance, circumstances favouring the stopping, and modality of withdrawal. Secondly, we analysed the different ways used by subjects to substitute their cocaine-dependence. PATIENTS AND METHODS: Cocaine-dependent subjects who had succeeded in supporting abstinence for at least 12 months without consumption were evaluated retrospectively by a face-to face interview. RESULTS: We obtained a list of circumstances associated with entries and exit from cocaine-dependence. Second, when seeking for similarities in addictive behaviour, before and after, between cocaine users, we proposed to classify patients according to the strength in their addictive dominant trait between strong, moderate, mild, or absence of addictive behaviour. For didactic aims, purposes are illustrated by clinical vignettes. CONCLUSIONS: This retrospective study allows us to clear arbitrarily four types of psychical modifications associated with prolonged abstinence in cocaine-dependent patients. Prospective clinical studies are clearly needed to standardize and to validate these clinical criteria.

Heterogeneity of stimulant dependence: a national drug abuse treatment clinical trials network study.

We investigated the presence of DSM-IV subtyping for dependence on cocaine and amphetamines (with versus without physical dependence) among outpatient stimulant users enrolled in a multisite study of the Clinical Trials Network (CTN). Three mutually exclusive groups were identified: primary cocaine users (n = 287), primary amphetamine users (n = 99), and dual users (cocaine and amphetamines; n = 29). Distinct subtypes were examined with latent class and logistic regression procedures. Cocaine users were distinct from amphetamine users in age and race/ethnicity. There were four distinct classes of primary cocaine users: non-dependence (15%), compulsive use (14%), tolerance and compulsive use (15%), and physiological dependence (tolerance, withdrawal, and compulsive use; 56%). Three distinct classes of primary amphetamine users were identified: non-dependence (11%), intermediate physiological dependence (31%), and physiological dependence (58%). Regardless of stimulants used, most female users were in the most severe or the physiological dependence group. These results lend support for subtyping dependence in the emerging DSM-V.

Client matching: a severity-treatment intensity paradigm.

Despite considerable effort to develop matching strategies and client placement protocols, research studies fail to yield compelling results regarding the benefits of matching to treatment. The most consistent findings suggest a matching paradigm, which defines a successful placement as the least treatment intensity required addressing the severity of the disorder. The purpose of the present study is to provide further empirical support for the validity of a severity-intensity paradigm utilizing data from the Drug Abuse Treatment Outcome Studies. A "passive match" approach employed the Client Matching Protocol decision algorithm, which recommended clients to long-term residential or outpatient drug-free treatment. One-year outcomes for clients matched to long-term residential treatment were better on all outcome variables compared to those undertreated in outpatient drug-free treatment. Findings supported the validity of the severity-intensity paradigm in that undertreated clients showed less improvement compared to matched and overtreated clients.

Health-related quality of life in young cocaine users and associated factors.

AIM: To analyse drug consumption patterns and demographic and medical factors associated with health-related quality of life (HRQL) in a nonclinical sample of regular cocaine consumers. METHODS: Face-to-face interviews with 687 young regular cocaine users (aged 18-30 years) in three Spanish cities: Barcelona, Madrid and Seville. HRQL was measured using the Nottingham Health Profile (NHP), and degree of dependence through the Severity of Dependence Scale (SDS). Bivariate analyses were conducted using nonparametric techniques, and a Tobit regression analysis was carried out to determine which variables best explained HRQL. RESULTS: Most participants showed a good HRQL, but differences in HRQL were found for sociodemographic (gender), medical (days stayed in bed during the previous 12 months) and consumption-pattern related variables (length of drug use, intravenous drug use, crack use, SDS). In multivariate analyses cocaine dependence measured by SDS explained the greatest amount of HRQL variation. Although women declared worse HRQL (13.6 versus 9.7, P < 0.01), in the final model with interactions no gender differences were observed, except that HRQL for women worsened with the number of days they had stayed in bed in the previous 12 months. CONCLUSIONS: Even in early phases of dependence, deterioration in HRQL is observed, mainly related to drug-use history and patterns.

Using the FFM to conceptualize psychopathy: a test using a drug abusing sample.

The present study examined whether psychopathy can be understood as a constellation of traits from the Five Factor Model (FFM) of personality. Using a prototype matching approach, we examined the ability of the Revised NEO Personality Inventory (NEO PI-R; Costa & McCrae, 1992) to represent psychopathy in a sample of 297 male and female known crack cocaine abusers. Importantly, we examined the convergence and divergence between FFM psychopathy and other personality disorders assessed using the FFM. FFM psychopathy was correlated with self-reports of antisocial behavior, drug use, risky sex, and externalizing and internalizing disorder symptoms. As expected, there was overlap in the relations between psychopathy and several Cluster B personality disorders, but there were also important points of divergence. These results further extend the nomological network of FFM psychopathy and provide additional support for considering psychopathy a constellation of personality traits from a general model.

Diagnosis of brain abnormality using both structural and functional MR images.

A number of neurological diseases are associated with structural and functional alterations in the brain. This paper presents a method of using both structural and functional MR images for brain disease diagnosis, by machine learning and high-dimensional template warping. First, a high-dimensional template warping technique is used to complete morphological and functional representation for each individual brain in a template space, within a mass preserving framework. Then, statistical regional features are extracted to reduce the dimensionality of morphological and functional representation , as well as to achieve the robustness to registration errors and inter-subject variations. Finally, the most discriminative regional features are selected by a hybrid feature method for brain classification, using a nonlinear support vector machine. The proposed method has been applied to classifying the brain images of prenatally cocaine-exposed young adults from those of socioeconomically matched controls, resulting in 91.8% correct classification rate using a leave-one-out cross-validation. Comparison results show the effectiveness of our method and also the importance of simultaneously using both structural and functional images for brain classification.

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

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

¿Es posible diferenciar analíticamente un consumidor de coca de uno de cocaína? / Is it possible to differentiate analitically a coca user from a coccaine user?

El objetivo del estudio fue ver si a través del análisis de orina se podría determinar el tipo de consumo de coca o cocaína que realizaban los consumidores. El estudio se llevó a cabo en la ciudad de La Paz (Bolivia). Para ello se reclutaron consumidores voluntarios y se dividieron en tres grupos: los consumidores de coca masticada (acullicadores), los consumidores de cocaína y los consumidores de coca en forma de mates. A todos ellos se les tomó muestras de orina con el fin de detectar la cantidad de benzoilecgonina y verificar si se podían establecer diferencias entre los individuos o los grupos. Cuando las concentraciones de benzoilecgonina en orina fluctuaban entre 220 a 450 ng/ml correspondían a cualquiera de los tres grupos consumidores sin poder descartar, ni diferenciar, ninguna de estas posibilidades. Cuando las concentraciones de benzoilecgonina en orina eran más altas y fluctuaban entre 451 a 560 ng/ml, correspondían a consumidores de hoja de coca que la masticaban (“acullicaban”) o a los consumidores de cocaína, sin poder descartar, ni diferenciar, ninguna de las dos posibilidades. La eliminación de benzoilecgonina por la orina, depende de la cantidad de coca/cocaína ingerida, de la forma de consumo de la coca, del metabolismo de la persona y de la cantidad de líquidos ingeridos/eliminados; pero no fue posible mediante esta prueba, saber a qué grupo pertenecía un individuo, pero sí se pudieron establecer diferencias grupales significativas entre las distintas formas de consumo

The objective of the study was to ascertain if urine analysis could be used to determine whether substance users were taking coca or cocaine. The study was carried out in the city of La Paz in Bolivia. Volunteer users were recruited and divided into three groups: those who chewed coca leaves, cocaine users and coca tea drinkers. Urine samples were taken from all of them, with the objective of detecting the amount of benzoylecgonine, and ascertaining if differences could be established between individuals or groups. When benzoylecgonine concentrations in urine fluctuated between 220 and 450 ng/ml, they corresponded to users in any of the three groups, it being impossible to discard or differentiate any one of them. When benzoylecgonine concentrations in urine were higher, and fluctuated between 451 and 560 ng/ml, they corresponded to those who chewed coca leaves or to cocaine users, without it being possible to discard or differentiate either of these two groups. The elimination of benzoylecgonine in the urine depends on the quantity of coca/cocaine ingested, the cocaine consumption method, personal metabolism and the quantity of liquid ingested/ eliminated but, on the basis of this study, it was not possible to ascertain to which group an individual belonged, although it was possible to establish significant group differences in accordance with the specific methods of use

Injection drug use and crack cocaine smoking: independent and dual risk behaviors for HIV infection.

PURPOSE: Previous studies have examined the practices of injecting drugs or smoking crack cocaine as high-risk, but independent, factors for HIV transmission. To explore the independent and dual risks of injection practices and crack smoking, this study examined HIV seroprevalence rates among distinct drug user groups, based on patterns of daily administration. METHODS: A sample of 3,555 drug users and neighborhood controls in urban Miami, FL and rural Belle Glade and Immokalee, FL were partitioned into four mutually-exclusive groups: 1) injection drug users (IDUs); 2) crack-cocaine smokers; 3) dual users who both smoked crack and injected drugs; and 4) non-drug-user controls. RESULTS: HIV seroprevalence rates were 45.1% for IDUs, 30.5% for dual users, 20.1% for crack smokers and 7.3% for controls. Multivariate logistic regression analysis found that when compared with controls odds ratios for HIV seropositivity were 9.81 for IDUs, 5.27 for dual users, and 2.24 for crack smokers. CONCLUSIONS: These findings provide evidence of: 1) behavioral and structural co-factors that influence HIV exposure patterns among drug users; and 2) the substantially higher risk of HIV infection among IDUs compared with other drug users. Intervention strategies must be tailored for the specific drug use subpopulations to optimize efficacy.

Cocaine dependence severity predicts outcome in outpatient detoxification from cocaine and alcohol.

This study compared the effects of alcohol and cocaine dependence severity on the outcome of outpatient detoxification from alcohol and cocaine. Subjects included 84 subjects with both alcohol and cocaine dependence admitted for outpatient detoxification. Fifty-three of the 84 subjects (63%) completed detoxification. Baseline cocaine use, cocaine craving, and cocaine withdrawal symptoms predicted detoxification outcome, whereas alcohol use, alcohol craving, and alcohol withdrawal symptoms did not. Among cocaine- and alcohol-dependent subjects, cocaine dependence severity appears to be a more important predictor of detoxification success than alcohol dependence severity.

Clínica de la adicción a pasta base de cocaína / Clinical features of cocaine base paste addiction

Introducción. El consumo de pasta base de cocaína (PBC) en Chile ha causado alarma aunque hay escasa información sobre la clínica del consumo. Se diseña un estudio exploratorio y descriptivo que busca precisar sus características. Material y método. Se registran los fenómenos clínicos en 61 pacientes consumidores de PBC, consultantes espontáneos de un centro tratamiento de adicciones en una comuna popular de Santiago, elegidos de modo aleatorio. Resultados. Alrededor de los dos meses de uso regular la PBC provoca conductas compulsivas de búsqueda y consumo de la sustancia. Es una adicción condicionada ya que la conducta compulsiva sólo aparece como respuesta a estímulos externos (principalmente la posesión de dinero) o internos (cambios anímicos o la fantasía de estar fumando). En un mismo individuo existen patones de consumo muy diferentes en un breve lapso de tiempo. Rápidamente se desarrolla sensibilización (hipertonia y estereotipias motoras, paranoia, ilusiones auditivas, visuales y cenestésicas, que son síntomas transitorios y vinculados al estado de intoxicación aguda) y tolerancia (disminución y desaparición del efecto euforizante). La sensibilización y la tolerancia aparecen simultáneamente y en conjunto con la conducta compulsiva. Cada episodio de consumo por lo general termina con intensos sentimientos de culpa, ansiedad y aún ideas suicidas. Existen una frecuente pérdida de normativas sociales y la constitución de un síndrome psicopático. Conclusiones. el consumo de PBC se ciñe a patrones de conducta muy variables pero siempre condicionadas a estímulos internos y externos, con poca o ninguna relación con la euforia, sugiriendo un fenómeno asociado a la neurobiología del aprendizaje.

Substance Dependence Severity Scale (SDSS): reliability and validity of a clinician-administered interview for DSM-IV substance use disorders.

No existing diagnostic interview assesses severity of dependence based on DSM-IV criteria across a range of substances. The Substance Dependence Severity Scale (SDSS) was designed to serve this purpose, consisting of substance-specific scales of both severity and frequency of DSM-IV criteria. This study investigated the reliability and validity of the SDSS. The test-retest reliability of the SDSS in 175 (112 male and 63 female) treated substance users ranged from good to excellent for alcohol, cocaine, heroin and sedatives (interclass correlation coefficients (ICCs)=0.75-0.88 for severity, 0.67-0.85 for frequency). Results for cannabis were lower, ranging from fair to good (ICCs=0.50-0.62). Results for joint rating and internal consistency reliability were comparable to test-retest findings. In addition to indicators of concurrent validity, scale applications are presented and discussed.