Background: There is growing evidence for recent declines in adolescent alcohol use in the Western world. While these changes have been subject to scientific debate, the reasons for this downward trend are not yet understood. Method: We consider broader theoretical framings that might be useful in understanding declines in youth drinking. In particular, we reflect on the historical observations of ‘long waves of alcohol consumption’, the ‘Total Consumption Model’, and the ‘Theory of Social Generations’. Based on this, we explore some of the main hypotheses that are presently discussed as possible explanations for changes in youth drinking. Results: We suggest there may have been a change in the social position of alcohol as a social reaction to the negative effects of alcohol, but also emphasize the importance of changes in technology, social norms, family relationships and gender identity, as well as trends in health, fitness, wellbeing and lifestyle behavior. As a result of the interplay of these factors, the ‘devaluation’ of alcohol and the use of it may have contributed to the decrease in youth drinking. Conclusions: For interrupting the recurrent cycle of the ‘long waves of alcohol consumption’, we need to take advantage of the present change in sentiment and “lock in” these changes by new control measures. The model of change presented here hinges on the assumption that the observed change in the position the present young generation takes on alcohol proceeds through the life course, eventually reducing alcohol use in the whole population.

Aims: The purpose of this paper is to summarize the psychometric properties of four short screening scales to assess problematic forms of cannabis use: Severity of Dependence Scale (SDS), Cannabis Use Disorders Identification Test (CUDIT), Cannabis Abuse Screening Test (CAST) and Problematic Use of Marijuana (PUM). Methods: A systematic computer-based literature search was conducted within the databases of PubMed, PsychINFO and Addiction Abstracts. A total of 12 publications reporting measures of reliability or validity were identified: 8 concerning SDS, 2 concerning CUDIT and one concerning CAST and PUM. Studies spanned adult and adolescent samples from general and specific user populations in a number of countries worldwide. Results: All screening scales tended to have moderate to high internal consistency (Cronbach's α ranging from .72 to .92). Test-retest reliability and item total correlation have been reported for SDS with acceptable results. Results of validation studies varied depending on study population and standards used for validity assessment, but generally sensitivity, specificity and predictive power are satisfactory. Standard diagnostic cut-off points that can be generalized to different populations do not exist for any scale. Conclusion: Short screening scales to assess dependence and other problems related to the use of cannabis seem to be a time and cost saving opportunity to estimate overall prevalences of cannabis-related negative consequences and to identify at-risk persons prior to using more extensive diagnostic instruments. Nevertheless, further research is needed to assess the performance of the tests in different populations and in comparison to broader criteria of cannabis-related problems other than dependence.

Aims: In Sweden, alcohol abstention has increased over the last 20 years and consumption has recently decreased after a peak in 2004. To understand the dynamics of these trends the present study aims at estimating age, period and cohort (APC) effects on trends in alcohol use prevalence as well as overall and beverage-specific volume of drinking over the last three decades. Methods: APC analysis of seven cross-sectional surveys from 1979 to 2011 was conducted using cross-classified random effects models (CCREMs) by gender. The nationally representative samples comprised 77,598 respondents aged 16–80 years. Outcome measures were 30-day prevalence of alcohol use and overall as well as beverage-specific alcohol volume. Results: Trends in prevalence, overall and beverage-specific volume were significantly affected by APC. The period effects of prevalence and overall volume show a small decline after an increase up to the year 2005. Mean beer and wine volume levelled off after a peak in 2005 and volume of spirits drinking decreased constantly. Predicted alcohol prevalence rates in male cohorts (1945–1985) remained generally at the same level, while they declined in post-World War II female generations. Results point to high overall and beverage-specific consumption among cohorts born in the 1940s, 1950s and 1980s. Conclusions: High consuming cohorts of the 1940–1950s were key in rising consumption up to 2005. Progression through the life course of these cohorts, a decrease in prevalence and drinking volume in successive cohorts seem to have contributed to the recent downward trend in alcohol use in Sweden.