Eyewitnesses to crimes are regularly under the influence of drugs, such as cannabis. Yet there is very little research on how the use of cannabis affects eyewitness memory. In the present study, we assessed the effects of cannabis on eyewitness recall and lineup identification performance in a field setting. One hundred twenty visitors of coffee…

This paper investigates how legal cannabis access affects student performance. Identification comes from an exceptional policy introduced in the city of Maastricht which discriminated legal access based on individuals' nationality. We apply a difference-in-difference approach using administrative panel data on over 54,000 course grades of local…

The goal of this study was to examine behavioral norm effects in 2 peer contexts (classroom, school) on adolescent substance use (tobacco, alcohol, cannabis) and aggressive behaviors (bullying, physical fighting). Participants were 5,642 adolescents (M[subscript age] = 14.29 years, SD = 1.26; 49% boys). There were 3 hypotheses. First, behavioral…

Background: Intellectually disabled offenders may have different characteristics than offenders with average intellectual functioning. We therefore compared pre-trial reported defendants with an IQ score =70, 71-84 and =85 points. Methods: Nationwide database of pre-trial psychiatric reports requested by Dutch courts between 2000 and 2006 with a…

Both music preferences and the substance use behavior of peers are important elements in explaining adolescent substance use. The extent to which music preference and peer use overlap in explaining adolescent substance use remains to be determined. A nationally representative sample of 7324 Dutch school-going adolescents (aged 12-16) provided data…

Previous studies from a wide variety of European countries have demonstrated that low educated adolescents engage more frequently in health risk behaviors compared to high educated adolescents. The present study investigates the mediating roles of parental knowledge and time spent with peers in this relationship. Data were retrieved from a…

Objective: Early-onset cannabis use has been associated with later use/abuse, mental health problems (psychosis, depression), and abnormal development of cognition and brain function. During adolescence, ongoing neurodevelopmental maturation and experience shape the neural circuitry underlying complex cognitive functions such as memory and…

Objective: To examine externalizing behavior problems and cigarette smoking as predictors of subsequent cannabis use. Method: Dutch adolescents (N = 1,606; 854 girls and 752 boys) from the TRacking Adolescents' Individual Lives Survey (TRAILS) ongoing longitudinal study were examined at baseline (ages 10-12 [T1]) and at two follow-up assessments…

The United States and the Netherlands have antithetical marijuana control policies. The United States' laws criminalize the possession of even small amounts of marijuana, while the Netherlands have maintained, over the past several decades, two relatively liberal marijuana policies implemented during the 1970s and 1980s. According to the…

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 up to 18 years who were ecstasy-naive at baseline but seemed likely to start taking ecstasy in the near future. After an 11- to…

The UK has the highest rate of cannabis use among young people worldwide. Dr. Alan Leshner, Director of the National Institute of Drug Abuse reports, "Every year more than 100,000 people, most of them adolescents, seek treatment for their inability to control their marijuana use." According to the Scottish Drug Misuse Statistics in…