Publications (4)12.83 Total impact
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ABSTRACT: To investigate the relationship between cannabis use and mental health. A cross-sectional analysis in a sample of 17 698 individuals with a mean age of 22 years (SD: 4.2). Participants provided information on the amount and initial age of cannabis use and history of psychiatric hospitalizations through a web-based questionnaire. To quantify Δ(9) -tetrahydrocannabinol exposure, we operationalized cannabis use as the amount of money spent on cannabis per week over the last month. The odds ratio of having a history of psychiatric hospitalizations was the primary outcome measure. We found a dose-response relationship between the amount of cannabis use and the odds for psychiatric hospitalization. Adjusted odds ratios for hospitalization increased with the amount of cannabis consumed from 1.6 (95% CI: 1.1-2.3) in incidental users to 6.2 (95% CI: 4.3-8.9) in heavy users (>€25/week). Our data suggested that concomitant drug use was an intermediate factor. Exposure to cannabis before the age of 12 years was found to carry a 4.8 (95% CI: 2.9-7.8) times increased odds for past psychiatric hospitalizations. We conclude that early and heavy uses of cannabis are each and independently associated with poor mental health in its users.Acta Psychiatrica Scandinavica 12/2010; 123(5):368-75. · 4.86 Impact Factor
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ABSTRACT: BACKGROUND: Cannabis use is associated with psychosis and a range of subclinical psychiatric symptoms. The strength of this association depends on dosage and age at first use. The current study investigates whether level of cannabis exposure and starting age are associated with specific profiles of subclinical symptoms.MethodWe collected cross-sectional data from a young adult population sample by administering an online version of the Community Assessment of Psychic Experiences (CAPE). Cannabis exposure was quantified as the amount of Euros spent on cannabis per week and the age of initial cannabis use. The primary outcome measure was the odds ratio (OR) to belong to the highest 10% of scores on the total CAPE and the positive-, negative- and depressive symptom dimensions. RESULTS: In 17 698 adolescents (mean age 21.6, s.d.=4.2 years), cannabis use at age 12 years or younger was strongly associated with a top 10% score on psychotic experiences [OR 3.1, 95% confidence interval (CI) 2.1-4.3] and to a lesser degree with negative symptoms (OR 1.7, 95% CI 1.1-2.5). The OR of heavy users (>€25/week) for negative symptoms was 3.4 (95% CI 2.9-4.1), for psychotic experiences 3.0 (95% CI 2.4-3.6), and for depressive symptoms 2.8 (95% CI 2.3-3.3). CONCLUSIONS: Early start of cannabis use is strongly associated with subclinical psychotic symptoms and to a lesser degree with negative symptoms, while smoking high amounts of cannabis is associated with increased levels of all three symptom dimensions: psychotic, negative and depressive. These results support the hypothesis that the impact of cannabis use is age specific.Psychological Medicine 10/2010; · 5.59 Impact Factor
- European Neuropsychopharmacology - EUR NEUROPSYCHOPHARMACOL. 01/2009; 19.
Article: Dutch medical oath.[show abstract] [hide abstract]
ABSTRACT: In the first part of this article, the booklet Dutch Medical Oath is reviewed. The content of the new oath is discussed as are the reasons for revision of the previous version of the oath. This is followed by a short history of the oath. In the second part of the article the oath is compared with the seven competencies of a medical specialist. The new oath contains elements of six of these seven competencies. This demonstrates that the oath is in keeping with the new medical educational demands.The Netherlands Journal of Medicine 11/2005; 63(9):368-72. · 2.38 Impact Factor