Search tips
Search criteria

Results 1-5 (5)

Clipboard (0)

Select a Filter Below

Year of Publication
Document Types
1.  Does Cannabidiol Protect Against Adverse Psychological Effects of THC? 
The recreational use of cannabis can have persistent adverse effects on mental health. Delta-9-tetrahydrocannabinol (THC) is the main psychoactive constituent of cannabis, and most, if not all, of the effects associated with the use of cannabis are caused by THC. Recent studies have suggested a possible protective effect of another cannabinoid, cannabidiol (CBD). A literature search was performed in the bibliographic databases PubMed, PsycINFO, and Web of Science using the keyword “cannabidiol.” After removing duplicate entries, 1295 unique titles remained. Based on the titles and abstracts, an initial selection was made. The reference lists of the publications identified in this manner were examined for additional references. Cannabis is not a safe drug. Depending on how often someone uses, the age of onset, the potency of the cannabis that is used and someone’s individual sensitivity, the recreational use of cannabis may cause permanent psychological disorders. Most recreational users will never be faced with such persistent mental illness, but in some individuals cannabis use leads to undesirable effects: cognitive impairment, anxiety, paranoia, and increased risks of developing chronic psychosis or drug addiction. Studies examining the protective effects of CBD have shown that CBD can counteract the negative effects of THC. However, the question remains of how the laboratory results translate to the types of cannabis that are encountered by real-world recreational users.
PMCID: PMC3797438  PMID: 24137134
tetrahydrocannabinol; cannabidiol; cannabis; psychosis; anxiety; drug dependence; cognition
2.  The Role of Study and Work in Cannabis Use and Dependence Trajectories among Young Adult Frequent Cannabis Users 
Life course theory considers events in study and work as potential turning points in deviance, including illicit drug use. This qualitative study explores the role of occupational life in cannabis use and dependence in young adults. Two and three years after the initial structured interview, 47 at baseline frequent cannabis users were interviewed in-depth about the dynamics underlying changes in their cannabis use and dependence. Overall, cannabis use and dependence declined, including interviewees who quit using cannabis completely, in particular with students, both during their study and after they got employed. Life course theory appeared to be a useful framework to explore how and why occupational life is related to cannabis use and dependence over time. Our study showed that life events in this realm are rather common in young adults and can have a strong impact on cannabis use. While sometimes changes in use are temporary, turning points can evolve from changes in educational and employment situations; an effect that seems to be related to the consequences of these changes in terms of amount of leisure time and agency (i.e., feelings of being in control).
PMCID: PMC3739012  PMID: 23950748
frequent cannabis use; cannabis dependence; young adults; qualitative research; life course approach; longitudinal study; education; employment
3.  The RT-18: a new screening tool to assess young adult risk-taking behavior 
Risk-taking behavior is a major determinant of health and plays a central role in various diseases. Therefore, a brief questionnaire was developed to assess risk taking among young adults with known different levels of risk-taking behavior (social drinkers and recreational drug users). In Study 1, N = 522 university students completed the RT-18 risk taking questionnaire. N = 100 students were retested after 2 to 4 weeks and performed the Cambridge Gambling Task (CGT). Mean RT-18 score was 7.69 and Cronbach’s alpha was 0.886. The test-retest reliability was r = 0.94. Significant correlation was found between the RT-18 score and CGT scores of risk taking, bet proportion, and risk adjustment. In Study 2, N = 7834 young adult social drinkers, and recreational drug users, mean RT-18 score was 9.34 and Cronbach’s alpha was 0.80. Factor analysis showed that the RT-18 comprises two factors assessing level of risk-taking behavior and risk assessment. Men scored significantly higher than women on the RT-18. Recreational drug users had significantly higher scores when compared to social drinkers. In Study 3 of N = 1000 students, construct validity was confirmed by showing that the RT-18 outcome correlates significantly with scores on the Stimulating-Instrumental Risk Inventory. In conclusion, the RT-18 is a valid and reliable screening tool to differentiate levels of risk-taking behavior. This short scale is quick and practical to administer, imposing minimal demands on participants. The RT-18 is able to differentiate risk taking and risk assessment which can help target appropriate intervention strategies.
PMCID: PMC3160867  PMID: 21887111
risk taking; impulsivity; sensation seeking; venturesomeness; novelty seeking
4.  Early Cannabis Use and Estimated Risk of Later Onset of Depression Spells: Epidemiologic Evidence From the Population-based World Health Organization World Mental Health Survey Initiative 
American Journal of Epidemiology  2010;172(2):149-159.
Early-onset cannabis use is widespread in many countries and might cause later onset of depression. Sound epidemiologic data across countries are missing. The authors estimated the suspected causal association that links early-onset (age <17 years) cannabis use with later-onset (age ≥17 years) risk of a depression spell, using data on 85,088 subjects from 17 countries participating in the population-based World Health Organization World Mental Health Survey Initiative (2001–2005). In all surveys, multistage household probability samples were evaluated with a fully structured diagnostic interview for assessment of psychiatric conditions. The association between early-onset cannabis use and later risk of a depression spell was studied using conditional logistic regression with local area matching of cases and controls, controlling for sex, age, tobacco use, and other mental health problems. The overall association was modest (controlled for sex and age, risk ratio = 1.5, 95% confidence interval: 1.4, 1.7), was statistically robust in 5 countries, and showed no sex difference. The association did not change appreciably with statistical adjustment for mental health problems, except for childhood conduct problems, which reduced the association to nonsignificance. This study did not allow differentiation of levels of cannabis use; this issue deserves consideration in future research.
PMCID: PMC2915487  PMID: 20534820
cannabis; depression; mental health; world health
5.  The Dutch Cannabis Dependence (CanDep) study on the course of frequent cannabis use and dependence: objectives, methods and sample characteristics 
This paper presents an overview of the prospective cohort design of the Dutch Cannabis Dependence (CanDep) study, which investigates (i) the three-year natural course of frequent cannabis use (≥ three days per week in the past 12 months) and cannabis dependence; and (ii) the factors involved in the transition from frequent non-dependent cannabis use to cannabis dependence, and remission from dependence. Besides its scientific relevance, this knowledge may contribute to improve selective and indicated prevention, early detection, treatment and cannabis policies. The secondary objectives are the identification of factors related to treatment seeking and the validation of self report measures of cannabis use.
Between September 2008 and April 2009, baseline data were collected from 600 frequent cannabis users with an average age of 22.1 years, predominantly male (79.3%) and an average cannabis use history of 7.1 years; 42.0% fulfilled a (12-month DSM-IV) diagnosis of cannabis dependence. The response rate was 83.7% after the first follow up at 18 months. The second and last follow-up is planned at 36 months. Computer assisted personal interviews (CAPI) were conducted which covered: cannabis use (including detailed assessments of exposure, motives for use and potency preference); use of other substances; DSM-IV internalizing and externalizing mental disorders; treatment seeking; personality; life events; social support and social functioning. Copyright © 2011 John Wiley & Sons, Ltd.
PMCID: PMC3467998  PMID: 21815231
design; frequent cannabis use; cannabis dependence; longitudinal

Results 1-5 (5)