Revisiting the concepts of risk and protective factors for understanding the etiology and development of substance use and substance use disorders: implications for prevention

Over the past 20 years we have accumulated a greater knowledge and understanding of the genetic, neurobiological, and behavioral factors that may be associated with young people initiating the use of drugs and other substances and to progressing from use to abuse and dependence. This knowledge suggests that individuals may be "predisposed" to substance use disorders (SUD) and that the actual engagement in these behaviors depends on their environmental experiences from micro to macro levels. This paper summarizes this knowledge base and supports a developmental framework that examines the interaction of posited genetic, psychological, and neurobiological "predispositions" to SUD and those environmental influences that exacerbate this vulnerability.

Research note: adolescents' perception of psychosis risk following cannabis consumption

Cannabis consumption during adolescence has been associated with the onset of psychosis. In 2010, we examined adolescents' perception of this association. Adolescents (N = 583) from four Romanian urban high schools filled in psychosis proneness scales according to the risk they assigned to hypothetical adolescents described in vignettes. Target adolescent's frequency and age of first consumption were manipulated. Analysis of variance indicated a main effect of target's consumption frequency, but no effect of age of first consumption on psychosis risk perception. Participants' own consumption status acted as moderator. Results highlight the discrepancy between clinical research results and adolescents' perception of psychosis risk. The study's limitations are noted.

The at-risk adolescent marijuana nonuser: expanding the standard distinction

This research expands the user/nonuser dichotomy commonly used in research on marijuana. By conceptualizing nonusers as homogeneous, vital nuances in susceptibility to risk and protective factors may be overlooked. Research operations tested the predictive validity of a brief measure that divided nonusers into resolute and vulnerable subcategories; determined whether variables that distinguished nonusers and users were more informative when a tripartite classification was used; and with an eye on future prevention, examined variables on which resolute nonusers were similar to vulnerable nonusers or users, and on which they differed from both. A nationally representative sample of respondents (N = 2,111; ages 12-16 years) from the National Survey of Parents and Youth was used in this secondary analysis. Panel data gathered yearly over four rounds included information on intentions and use of marijuana and other illicit substances, along with social, demographic, intrapersonal, and parental variables. The three groups differed significantly on associates' marijuana use, participants' approval of others' use, and cigarette and alcohol use. Resolute nonusers differed from vulnerable nonusers and users alike on religiosity, delinquency (self and friends'), refusal strength, sensation seeking, parental monitoring and warmth, and adult supervision. Results support the utility of distinguishing vulnerable from resolute nonusers, counsel against considering nonusers as a homogeneous group, and provide insight into variables that might prove useful in future prevention efforts.

The role of peers in the initiation and continuation of ecstasy use

This study is a supplement to the Netherlands XTC Toxicity Study (NeXT), funded by grants from the Netherlands Organisation for Health Research and Development as part of its Addiction Programme. To better understand the processes of peer influence and peer selection, in a field study 106 Ecstasy users (67M/39F, average age 25.4 years) were interviewed face-to-face in Amsterdam in 2005. In the initiation of Ecstasy use, peer influence emerged as the dominating mechanism; peer selection was uncommon. In the continuation of Ecstasy use, peer influence and peer selection occurred reciprocally in a dynamic process, although peer influence made a greater relative contribution. Our study confirms that peer influence is a multidimensional process: influence was quite often reciprocal (with respondents both exerting and undergoing influence) and it could have both restraining and encouraging effects on ecstasy use. The study's limitations are noted.

Social cognitive determinants of ecstasy use to target in evidence-based interventions: a meta-analytical review

AIMS

The health hazards and prevalence of ecstasy use have been documented in two decades of research, but no review reporting on potentially modifiable antecedents of use is available. The aim of this study was to integrate systematically research identifying cognitive correlates of ecstasy use. Such research has the potential to identify targets for evidence-based interventions designed to discourage use.

METHODS

The databases PsycINFO and MedLine were searched, inclusion criteria applied to resulting hits, and descendency and ancestry approaches applied to the selected publications. Reported associations between cognitive determinants, including intention to use and ecstasy use measures, were synthesized by calculating a weighted mean effect size, r.

RESULTS

The pattern of associations lent support both to the theory of planned behaviour (TPB) and the expectancy approach as descriptions of potentially useful determinants. Attitudes were associated most strongly with intention and use, followed by subjective norm and perceived behavioural control.

CONCLUSIONS

Consideration of the strength of associations and the potential modifiability of identified cognitions suggests that evidence-based interventions to discourage ecstasy use should target negative expectancies, perceived behavioural control and anticipated regret, and consider tailoring perceived behavioural control elements.

Predicting ecstasy use among young people at risk: a prospective study of initially ecstasy-naive subjects

Our aim is to identify predictors of first-time ecstasy use in a prospective study among young people at risk. As part of the multidisciplinary Netherlands XTC Toxicity Study (NeXT), we monitored 188 subjects aged > or = 18 who were ecstasy-naive at baseline but seemed likely to start taking ecstasy in the near future. After an 11- to 26-month follow-up period, 160 respondents remained (85.1%; mean age 21.0 years, 58.1% females): 65 who took ecstasy at least once (ecstasy users) and 95 non-users. At baseline and four times during follow-up, respondents completed self-report questionnaires. Cox regression analysis was used to examine the effects of baseline respondent characteristics on incident ecstasy use. Development of peer group ecstasy use was analyzed by logistic regression. Intention to use ecstasy, low education, and current weekly cannabis use independently increased the hazard rate for first ecstasy use. Although ecstasy use among peers at baseline was not a predictor, the proportion of ecstasy users with ecstasy-using peers increased markedly during the study. Our results suggest that targeted prevention activities should focus in particular on young people who have strong intentions to take ecstasy, especially if they are also regular smokers of cannabis.

How to find future ecstasy-users: targeted and snowball sampling in an ethically sensitive context

This article documents the design and the sampling procedures of a prospective longitudinal multidisciplinary study on the neurotoxicity of ecstasy (MDMA): the Netherlands XTC Toxicity Study (NeXT). Targeted and snowball sampling was used to recruit 188 respondents who were ecstasy-naive at baseline. All respondents completed baseline questionnaires and underwent medical and neuropsychological examinations. At the end of a 11- to 26- month follow-up period in which they completed four additional questionnaires, 160 respondents remained (85.1%). A total of 65 participants (40.6%) took ecstasy for the first time during the follow-up period. This paper discusses the ethical dilemmas inherent in a study of this type and the specific problems and solutions that emerged in the sampling. The sampling was tightly constrained by our need to locate respondents who were potential future ecstasy users while also meeting strict medical and technical criteria. The 'intention to use' criterion proved to be a clear-cut inclusion rule that was practical to apply in the fieldwork.