Charles D. Kaplan

Prospective cohort study of cannabis use, predisposition for psychosis, and psychotic symptoms in young people

Abstract Objective To investigate the relation between cannabis use and psychotic symptoms in individuals with above average predisposition for psychosis who first used cannabis during adolescence. Design Analysis of prospective data from a population based sample. Assessment of substance use, predisposition for psychosis, and psychotic symptoms was based on standardised personal interviews at baseline and at follow up four years later. Participants 2437 young people (aged 14 to 24 years) with and without predisposition for psychosis. Main outcome measure Psychotic symptoms at follow up as a function of cannabis use and predisposition for psychosis at baseline. Results After adjustment for age, sex, socioeconomic status, urbanicity, childhood trauma, predisposition for psychosis at baseline, and use of other drugs, tobacco, and alcohol, cannabis use at baseline increased the cumulative incidence of psychotic symptoms at follow up four years later (adjusted odds ratio 1.67, 95% confidence interval 1.13 to 2.46). The effect of cannabis use was much stronger in those with any predisposition for psychosis at baseline (23.8% adjusted difference in risk, 95% confidence interval 7.9 to 39.7, P = 0.003) than in those without (5.6%, 0.4 to 10.8, P = 0.033). The risk difference in the “predisposition” group was significantly greater than the risk difference in the “no predisposition” group (test for interaction 18.2%, 1.6 to 34.8, P = 0.032). There was a dose-response relation with increasing frequency of cannabis use. Predisposition for psychosis at baseline did not significantly predict cannabis use four years later (adjusted odds ratio 1.42, 95% confidence interval 0.88 to 2.31). Conclusion Cannabis use moderately increases the risk of psychotic symptoms in young people but has a much stronger effect in those with evidence of predisposition for psychosis.

Reaching the unreached : targeting hidden IDU populations with clean needles via known user groups

Needle exchange is a practical and important part of the Dutch prevention strategy to check the spread of HIV among injecting drug users (IDUs). However, needle-exchange programs are often tied to drug treatment programs that only reach a limited number of IDUs. To overcome this limitation, alternative designs are considered and initiated. This article describes a community-based approach to needle exchange that is built on empowerment of, and intense participation by, known IDUs to target unknown IDUs for delivery of clean needles. The needle-exchange patterns of the IDUs participating in this collective scheme are compared to those of other users who exchanged needles on an individual basis. It was found that this approach extended the reach of the program to a great degree and that it was well received in the IDU community. However, the results were negatively influenced by police activities aimed at closing down places where drugs were used and sold. It is concluded that engaging IDUs in peer-group-directed prevention efforts is both feasible and promising.

Prevalence of psychopathology in drug-addicted Dutch

In Dutch samples of treated heroin addicts, high prevalences of a heterogeneous psychiatric co-morbidity can be found with regard to Diagnostic and Statistical Manual (third edition) (DSM-III) classifications, Zung Depression Inventory, and sum scores of a 90-item Symptom Checklist (SCL-90). A high-threshold (N = 87) and a low-threshold (N = 116) program are compared with regard to psychopathology and severity of psychopathology. A consecutive admissions design was used. More than 50% of the respondents suffered from a lifetime DSM-III Axis I disorder (70% with antisocial personality disorder included), and 40% were still suffering from one of the disorders in the year preceding the interview. Schizophrenia was diagnosed five times as much as in normal population samples (5%). The most frequently diagnosed disorders were recurrent major depression, phobic disorders, alcohol abuse and dependence, dysthymic disorder, and antisocial personality disorder. The prevalences of DSM-III disorders, the total number of symptoms, and the score on the Zung Depression Inventory and 90-item Symptom Checklist were all significantly higher in treatment-seeking drug addicts entering the high-threshold program. Within each program, three clinically meaningful subgroups can be distinguished: one group with DSM-III Axis I lifetime or current psychopathology and/or antisocial personality disorder, one with antisocial personality disorder only, and one with neither DSM-III psychopathology nor antisocial personality disorder. Possibly, self-selection results in patients with more serious conditions entering more treatment-oriented facilities. Odds ratios show that schizophrenia and mood disorders and especially associated on a lifetime and current basis.

Psychopathy among Mexican American Gang Members: A Comparative Study

High-risk Mexican American males were assessed for levels of psychopathy. The Hare Psychopathy Checklist–Screening Version was compared in a random sample of gang members with a matched community sample of violent non-gang members and samples of forensic and psychiatric patients and undergraduate students. Analysis involved t-test, chi- square, and Cronbach’s alpha statistics. More than half of the gang sample were categorized as low, 44% as moderate, and only 4% as high on psychopathy. The gang members had higher scores on the total, affective, and behavioral scores than the non–gang members. High scores on adolescent antisocial behavior, poor behavioral controls, and lack of remorse were found in both samples. Gang members scored twice as high as non-gang members on lack of empathy. Both samples were lower on psychopathy than the forensics and higher than psychiatric patients and undergraduates. The results provide grounds for early intervention efforts for this high-risk population.

The Prospects and Limitations of Compulsory Treatment for Drug Addiction

During the 1980s, social scientists and policy makers have been examining the different kinds of pressures that affect the behavior of drug addicts, and have been discussing how these pressures may be better managed to get addicts into treatment, to change their drug-related behaviors during treatment, and to maintain these changes following treatment. This article reviews the pressures inherent in the legal, social, and treatment systems of the United States of America and the Federal Republic of Germany, and discusses the utility of combining elements of the legal and treatment systems. The article presents six propositions summarizing the conclusions reached at a conference regarding the assessment and use of pressures in addiction treatment. The article also presents the final recommendations that were made. It was concluded that the present lack of knowledge about the effectiveness of compulsory treatment raises ethical, as well as practical questions. Although compulsory treatment is a tempting solution to the drug addiction problem, a complete social policy analysis of the use of coercive pressure must be undertaken before acceptance would be appropriate. Compulsory treatment must be judged not in terms of moralistic ideas or political expediency, but in terms of the entire range of treatment policy options.

A comparison of alcohol, drugs, and aggressive crime among Mexican-American, black, and white male arrestees in Texas.

Few comparative studies exist examining the relationship between substance abuse and aggressive behavior under different social conditions. We studied the relationship between aggressive crime and substance abuse among Mexican-American, black and white male arrestees in Dallas, Houston, and San Antonio, Texas using existing 1992 Drug Use Forecasting (DUF) data. The aim of the analysis was to predict the outcome of aggressive crime from drug and alcohol-related and ethnic group variables within the total male sample (n = 2,364). Results indicated that ethnicity was significantly related to aggressive crime. Mexican-American arrestees were more likely to be arrested for aggressive crimes than either blacks or whites. Drug and alcohol use effects were found across all ethnic groups. In general, the subgroup which drank frequently and tested positive for drug use was less likely to be charged with aggressive crimes than the other subgroups. The psychopharmacological influence of alcohol as a disinhibitor and drugs as a inhibitor provides one explantation of the results. Specific ethnic subcultural and ecological influences also affect the outcome. Our study strongly indicates the heterogeneous character of the drug using population in relation to aggression. The variability between subculturally defined subgroups requires detained ethnographic field studies in the future to describe the contexts of substance use and aggressive behavior.

Illegal drug use, alcohol and aggressive crime among Mexican-American and white male arrestees in San Antonio

This research explores the relationship between use of certain drugs and aggressive crimes among Mexican-American and White male arrestees in San Antonio, Texas, for 1992. This is based on a Drug Use Forecasting (DUF) sample of 534 male arrestees administered a drug urine analysis test and questionnaire by the Department of Justice and the city of San Antonio. Using a four-way asymmetrical analysis, logit-models were tested to examine the relationships between the response variable, the types of crimes charged (nonaggressive versus aggressive) and a set of exploratory variables, ethnicity (White versus Hispanic), drug test results (positive versus negative), and alcohol use (infrequent versus frequent). The logit-analysis allows the specification of a subset of relevant models to be tested for their adequacy of fit. Findings indicate a complex but interpretable pattern between drug use, alcohol use patterns, and aggressive crimes. A surprising finding was that more aggressive crimes were committed by all men testing negative for drugs. Mexican-Americans with frequent alcohol use and testing positive for drugs were twice as likely to commit an aggressive crime (a crime associated with violence) than Whites in the same subgroup. The implication of these findings for prevention strategies aimed at alcohol and other drug users involved in violent behavior is discussed.

The importance of active lifestyles for memory performance and memory self-knowledge

The relation between knowledge about memory capacity, delayed recall on a 15-word-list task, and sociological lifestyle variables was examined in a sample of 1,398 adults ranging in age between 25 and 82. Participants were sampled from a registration network of family medical practices representing the general population of the south of The Netherlands. Participants were stratified for age, sex, and level of occupational achievement. We found that lifestyle opportunity structure as indicated by social network characteristics and lifestyle conduct as indicated by activity scores were related positively to the dependent variables of memory knowledge and delayed recall. Study results showed that participants with better delayed recall scores had larger social networks, were younger, were more frequently female, had more years of education, and were less externally oriented. Participants with higher metamemory capacity scores had more frequent contacts in their social network, considered themselves more frequently an active person, were younger, were female, reported fewer health complaints, and had a higher internal locus of control. Delayed recall scores did not predict metamemory capacity scores after we controlled for other variables. The results support the conclusion that cognitive performance is influenced significantly by lifestyle components.

The Influence of Family and Peer Risk Networks on Drug Use Practices and Other Risks among Mexican American Noninjecting Heroin Users

Noninjecting heroin use (NIU) is spreading among social networks of young Mexican American polydrug users. This article examines the influence of family and peer networks on NIU behavior and other drug practices and risks. This study delineates the extent to which a culturally relevant modification of the “network facilitation” theoretical approach can increase both a theoretical and practical understanding of drug use and related risk behaviors. Using the methods of analytic ethnography, it identifies, describes, and explains variations in the social networks among this marginalized population and how specific aspects of Mexican American culture (familismo, and collectivismo) affects risk behaviors.

L-Methadone and D,L-Methadonein Methadone Maintenance Treatment: A Comparison of Therapeutic Effectiveness and Plasma Concentrations

The clinical effectiveness of l-methadone maintenance treatment (LMMT) carried out using d,l-methadone or l-methadone have been compared with ambulatory heroin-dependent subjects. A total of 40 heroin-dependent subjects, previously maintained on l-methadone in Frankfurt am Main, were divided into two groups under randomised double-blind conditions and received either an equivalent dose of l-methadone as d,l-methadone or remained on the previous l-methadone treatment. Requests for a change in the dose of d,l-methadone and l-methadone were recorded, urine samples for determination of illicit drug use were collected and the individual level of opiate craving was determined over a 22-day observation period. There was no significant difference between the two groups in the number requests for a dose change (dose increase <10%). However, there was a significant increase in heroin use in the group which continued to receive l-methadone. Although there was less variability in opiate craving in the group receiving d,l-methadone, the mean intensity of opiate craving did not differ between the two groups. The mean l-methadone dose:l-methadone plasma concentration ratio, an index of the bioavailability of l-methadone in individual subjects, showed no significant change when the treatment was changed to d,l-methadone. The mean d-methadone:l-methadone plasma concentration ratio was 1.17. There was no significant difference between these ratios for day 15 and day 22. The mean l-methadone:EDDP plasma concentration ratio in the l-methadone group was 22.2 and the d,l-methadone:EDDP plasma concentration ratio was 18.4 . The plasma EDDP concentration in the d,l-methadone group increased 3-fold after starting treatment with d,l-methadone. These findings suggest that d,l-methadone can be used in methadone maintenance treatment of heroin-dependent subjects but that further studies are required to evaluate pharmacokinetic interactions between methadone enantiomers.