Details

dr. Margriet van Laar

Position
Head Drug Monitoring & Policy/Reitox Focal Point
Program
Drug Monitoring & Policy
Telephone
+31 (0)30 - 2959(320)
E-mail
Contact page
Margriet van Laar

Expertise

After my PhD in human psychopharmacology at the Utrecht Institute for Pharmaceutical Sciences, I closely studied developments in substance use and misuse for several decades. This includes epidemiological research on the use and health effects of licit and illicit substances in various populations, but also policy evaluations and demand reduction.

As the hub and coordinator of Trimbos’ drug research, I  share knowledge and expertise in several national and international advisory committees, e.g.:

  • Coordinator of the National Drug Monitor (NDM) and editor-in-chief of the Annual reports of the NDM (@Trimbos)
  • Inaugural coordinator of the Netherlands Expertise Center on Tobacco Control (NET) (@Trimbos)
  • Chair of the Risk Assessment Committee of the National Centre for the Assessment and Monitoring of new drugs of misuse
  • Head of the Dutch Reitox National Focal Point (NFP) of the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA)

Inspiration and mission

At the start of my career as a researcher in the field of substance, the debate on drugs was highly polarized and resting on untested assumptions and ideologies, both within the Netherlands and worldwide between different nations. Within the battlefield of viewpoints and incomparable and flawed statistics, I got inspired by the evidence-based ‘movement’ spreading from the field of medicines. My mission is to contribute to a solid ‘evidence base’ to inform and strengthen policies aimed at preventing and reducing health and societal damage related to substance use.

As the drug problem is a multifaceted, dynamic and complex phenomenon, simple answers are often not available. I am particularly inspired by bringing together different fields of expertise and thus contribute to defining the appropriate health and policy responses.

Currently working on..

Research topics include drug market estimates, substance use in the nightlife scene, health effects of cannabis, drug-related mortality, evaluation of policies and risk (assessments) of illicit drugs and NPS, emerging trends.

Key projects/activities include:

  • The National Drug Monitor (NDM) producing annual reports with an extensive overview of trends in substance use and drug-related criminality, in co-operation with the Research and Documentation Centre of the Ministry of Security and Justice
  • Monitoring the online drug markets and user fora and New Psychoactive Substances (e.g. 4-FA, fentanyls)
  • Eranid project ALAMA, a study on  the dynamics of substance use in relation to the nightlife scene in 5 EU countries
  • Development of an online cannabis e-health intervention

Freeman, T.P., Pol, P. van der, Kuijpers, W., Wisselink, J., Da, R.K., Rigter, R., Laar, M. van, ... Niesink, R. (2018). Changes in cannabis potency and first-time admissions to drug treatment: a 16-year study in the Netherlands. Psychological Medicine. doi:10.1017/S0033291717003877

Mujcic, A., Blankers, M., Boon, B., Engels, R., & Laar, M. van (2018). Internet-based self-help smoking cessation and alcohol moderation interventions for cancer survivors: a study protocol of two RCTs. BMC Cancer, 18(364). doi:10.1186/s12885-018-4206-z

Vreeker, A., Burg, B.G. van der, Laar, M. van, & Brunt, T.M. (2017). Characterizing users of newpsychoactive substances using psychometric scales for risk-related behavior. Addictive Behaviors, 70(juli), 72-78. doi:10.1016/j.addbeh.2017.02.010

Witkam, R., Monshouwer, K., Drost, Y., Laar, M. van & Pol, P. van der (2017). Wat doen XTC-gebruikers om risico’s te beperken? Verslaving. doi:10.1007/s12501-017-0111-4

Blankers, M., Buisman, R., Hopman, P., Gool, R. van & Laar, M. van (2016). Modelling intentions to provide smoking cessation support among mental health professionals in the Netherlands. Tobacco Induced Diseases, 14(31). doi:10.1186/s12971-016-0096-5

Blankers, M., Smit, E.S., Pol, P. van der, Vries, H. de, Hoving, C., & Laar, M. van (2016). The missing=smoking assumption: A fallacy in internet-based smoking cessation trials? Nicotine & Tobacco Research, 18(1), 25-33. doi:10.1093/ntr/ntv055

Gouwe, D. van der, Brunt, T.M., Laar, M. van, & Pol, P. van der (2016). Purity, adulteration and price of drugs bought online versus offline in the Netherlands. Addiction. doi:10.1111/add.13720

Laar, M. van, Pol, P. van der, & Niesink, R . (2016). Limitations to the Dutch cannabis toleration policy : Assumptions underlying the reclassification of cannabis above 15% THC. International Journal of Drug Policy. doi:10.1016/j.drugpo.2016.02.011

Benschop, A., Liebregts, N., Pol, P. van der, Schaap, R., Buisman, R., Laar, . . . Graaf, R. de (2015). Reliability and validity of the Marijuana Motives Measure among young adult frequent cannabis users and associations with cannabis dependence. Addictive Behaviors, 40, 91-95. doi:10.1016/j.addbeh.2014.09.003

Buisman R., Blankers, M., & van Laar, M. (2015). Het gebruik van e-sigaretten onder Nederlandse jongeren: Een verkennend onderzoek [Electronic cigarette use among adolescents in the Netherlands]. Verslaving : Tijdschrift over Verslavingsproblematiek, 11(2), 77-88. doi:10.1007/s12501-015-0017-y

Kuipers, M.A.G., Monshouwer, K., Laar, M. van, & Kunst, A.E. (2015). Tobacco control and socioeconomic inequalities in adolescent smoking in Europe. American Journal of Preventive Medicine , 49(5), 64-72. doi.org/10.1016/j.amepre.2015.04.032

Laar, M., Pol, P. van der, & Niesink, R. (2015). Grenzen aan gedogen: Uitgangspunten 15% THC-maatregel nader beschouwd. Verslaving, 11(1), 44-56. doi:10.1007/s12501-015-0006-1

Liebregts, N., Pol, P. van der, Graaf, R. de, Laar, M. van, & Brink, W. van den, Korf, D.J. (2015). Persistence and desistance in heavy cannabis use: The role of identity, agency, and life events. Journal of Youth Studies, 18(5), 617-633 . doi:10.1080/13676261.2014.992320

Liebregts, N., Pol, P. van der, Laar, M. van, Graaf, R. de, & Brink, W. van den, & Korf, D.J. (2015). The role of leisure and delinquency in frequent cannabis use and dependence trajectories among young adults. International Journal of Drug Policy, 26(2), 143-152. doi:10.1016/j.drugpo.2014.07.014

Linsen, F., Koning, R.P.J., Laar, M. van, Niesink, R.J.M., Koeter, & M.W., Brunt, T.M. (2015). 4-Fluoroamphetamine in the Netherlands: more than a one-night stand. Addiction, 110(7), 1138–1143. doi:10.1111/add.12932

Pol, P. van der, Liebregts N., Graaf, R. de, Korf D., Brink, W. van den, & Laar, M. van (2015). Three-year course of cannabis dependence and prediction of persistence. European Addiction Research, 21(6), 279-290. doi:10.1159/000377625

Pol, P. van der, Liebregts, N., Graaf, R. de, Korf, D.J., Brink, W. van de, & Laar, M. van (2015). Wel of geen hulp zoeken voor cannabisafhankelijkheid? Verslaving, 11(2), 103-115. doi:10.1007/s12501-015-0016-z

Vermeulen-Smit, E., Have, M. ten, Laar, M. van, & Graaf, R. de (2015). Clustering of health risk behaviours and the relationship with mental disorders. Journal of Affective Disorders, 171, 111-119. doi:10.1016/j.jad.2014.09.031

Blankers, M., Frijns, T., Belackova, V., Rossi, C., Svensson, B., Trautmann, F., Laar, M. van (2014). Predicting Cannabis Abuse Screening Test (CAST) scores: A recursive partitioning analysis using survey data from Czech Republic, Italy, the Netherlands and Sweden. PLoS ONE, 9(9). doi:10.1371/journal.pone.0108298

Pol, P. van der, Liebregts, N., Brunt, T., Amsterdam, J. van, Graaf, R. de, Korf, D.J., Laar, M. van (2014). Cross-sectional and prospective relation of cannabis potency, dosing and smoking behaviour with cannabis dependence: An ecological study. Addiction, 109(7), 1101-1109. doi:10.1111/add.12508

Castaldelli-Maia, J.M., Martins, S.S., Oliveira, L.G. de, Laar, M. van, Andrade, A.G. de, Nicastri, S. (2013). Use transition between illegal drugs among Brazilian university students. Social Psychiatry and Psychiatric Epidemiology. doi:10.1007/s00127-013-0748-1

Laar, M. van, Frijns, T., Trautmann, F., Lombi, L. (2013). Surveys on user types, availability and consumption estimates. In F. Trautmann (ed.), B. Kilmer (ed.), P. Turnbul (ed.), Further insights into aspects of the EU illicit drugs market: summaries and key findings (pp. 15-22). Luxembourg: Publications Office of the European Union,. doi:10.2838/4281

Laar, M. van, Frijns, T., Trautmann, F., Lombi, L. (2013). Sizing the cannabis market: a demand-side and user-specific approach in seven European countries. Current Drug Abuse Reviews, 6(3). doi:10.2174/1874473706666131205152835

Liebregts, N., Pol, P. van der, Laar, M. van, Graaf, R. de, Brink, W. van den, Korf, D.J. (2013). The role of parents, peers and partners in cannabis use and dependence trajectories among young adult frequent users. Contemporary Drug Problems, 40, 531-568.

Liebregts, N., Pol, P. van der, Laar, M. van, Graaf, R. de, Brink, W. van den, Korf, D.J. (2013). The role of study and work in cannabis use and dependence trajectories among young adult frequent cannabis users. Frontiers in Psychiatry, 4. doi:10.3389/fpsyt.2013.00085

Niesink, R.J.M., Laar, M.W. van (2013). Does cannabidiol protect against adverse psychological effects of THC? Frontiers in Psychiatry, 4(130). doi:10.3389/fpsyt.2013.00130

Pol, P. van der, Liebregts, N., Graaf, R. de, Have, M. ten, Korf, D.J., Brink, W., Laar, M. ten (2013). Mental health differences between frequent cannabis users with and without dependence and the general population. Addiction, 108(8), 1459-1469. doi:10.1111/add.12196

Pol, P. van der, Liebregts, N., Graaf, R. de, Korf, D.J., Brink, W. van den, Laar, M. van (2013). Predicting the transition from frequent cannabis use to cannabis dependence: A three-year prospective study. Drug and Alcohol Dependence, 133(2), 352– 359. doi: 10.1016/j.drugalcdep.2013.06.009

Pol, P. van der, Liebregts, N., Graaf, R. de, Korf, D.J., Brink, W. van den, Laar, M. van (2013). Validation of self-reported cannabis dose and potency: an ecological study. Addiction, 108(10), 1801–1808. doi:10.1111/add.12226

Pol, P. van der, Liebregts, N., Graaf, R. de, Korf, D.J., Brink, W. van den, Laar, M. van (2013). Facilitators and barriers in treatment seeking for cannabis dependence. Drug and Alcohol Dependence, 133(2), 776– 780. doi:10.1016/j.drugalcdep.2013.08.011

Pol, P. van der, Liebregts, N., Graaf, R. de, Korf, D.J., Brink, W. van den, Laar, M. van (2013). Reliability and validity of the Severity of Dependence Scale for detecting cannabis dependence in frequent cannabis users. International Journal of Methods in Psychiatric Research, 22(2), 138–143. doi:10.1002/mpr.1385

Amsterdam, J.G.C. van, Laar, M. van, Brunt, T.M., Brink, W. van den (2012). Risk assessment of gamma-hydroxybutyric acid (GHB) in the Netherlands. Regulatory Toxicology and Pharmacology, 63(1), 55–63. doi:10.1016/j.yrtph.2012.03.005

Laar, M. van (2012). Epidemiology of alcohol and drug use. In J.C. Verster (ed.), K. Brady (ed.), M. Galanter (ed.), P. Conrod (ed.), Drug abuse and addiction in medical illness: causes, consequences and treatment (pp. 3-24). New York: Springer.

Niesink, R., Laar, M. van (2012). Cannabidiol: de nieuwe haarlemmerolie of een hype? Verslaving : Tijdschrift over Verslavingsproblematiek, 8(2), 63-77.

Wouters, M., Wouters, A., Laar, M. van, Korf, D.J. (2012). Cannabis use and proximity to coffee shops in the Netherlands. European Journal of Criminology, 9(4), 337–353. doi:10.1177/1477370812448033

Haan L. de, Kuipers, E., Kuerten, Y., Laar, M. van, Olivier, B., Verster, J.C. (2011). The RT-18: a new screening tool to assess young adult risk-taking behavior. International Journal of General Medicine, 4, 575 - 584. doi:10.2147/IJGM.S23603

Laar, M. van (2011). LADIS: bouwsteen van formaat voor de Nationale Drug Monitor. In D. van de Mheen (inl.), Verslaafd aan informatie?! 25 jaar Landelijk Alcohol en Drugs Informatie Systeem (LADIS), informatie over verslaving en verslavingszorg (pp. 66-75). Houten: Stichting Informatievoorziening Zorg.

Liebregts, N., Benschop, A., Pol, P. van der, Laar, M. van, Graaf, R. de, Brink, W. van den, Korf, D.J. (2011). Cannabis dependence and peer selection in social networks of frequent users. Contemporary Drug Problems, 38(1), 93-119.

Monshouwer, K., Laar, M. van, Vollebergh, W.A. (2011). Buying cannabis in 'coffee shops'. Drug and Alcohol Review, 30(2), 148-156.

Ooyen-Houben, M. van, Laar, M. van (2011). Nut en nood van coffeeshops. Secondant, 25(3/4), 28-33.

Pol, P. van der, Liebregts, N., Graaf, R. de, Korf, D. J., Brink, W. van de, Laar, M. van (2011). The Dutch Cannabis Dependence (CanDep) study on the course of frequent cannabis use and dependence:objectives, methods and sample characteristics. International Journal of Methods in Psychiatric Research, 20(3), 169–181. doi:10.1002/mpr.345

Brunt, T.M., Laar, M. van, Niesink, R.J.M., Brink, W. van den (2010). The relationship of quality and price of the psychostimulants cocaine and amphetamine with health care outcomes. Drug and Alcohol Dependence, 111, 21-29.

Graaf, R. de, Radovanovic, M., Laar, M. van, Fairman, B., Degenhardt, L., Aguilar-Gaxiola, S., Bruffaerts, R., De Girolamo, G., Fayyad, J. (2010). Early cannabis use and estimated risk of later onset of depression spells: epidemiological evidence from the population-based World Health Organization World Mental Health Survey Initiative. American Journal of Epidemiology, 172(2), 149-159.

Laar, M. van, Monshouwer, K., Brink, W. van den (2010). Roken, drinken en blowen door de Nederlandse jeugd. Kind en adolescent, 31(4), 204-220.

Niesink, R., Laar, M. van (2010). Cannabis en verslaving: feiten en misverstanden. Verslaving : Tijdschrift over Verslavingsproblematiek, 6(4), 84-96.

Verster, J.C., Kuerten, Y., Olivier, B., Laar, M.W. van (2010). The ACID-Survey: methodology and design of an online survey to assess alcohol and recreational cocaine use and its consequences for traffic safety. The Open Addiction Journal, 3, 24-31.

Cruts, A.A.N., Feenstra, T.L., Laar, M.W. van (2008). Ziekte door roken in Nederland: naar schatting 90 duizend klinische ziekenhuisopnamen in 2005. Nederlands Tijdschrift voor Geneeskunde, 152(26), 469-472.

Cruts, G., Buster, M., Vicente, J., Deerenberg, I., Laar, M. van (2008). Morbidity: Estimating the total mortality among problem drug users. Substance Use & Misuse, 43(5), 733–747.

Verdurmen, J., Mheen, D. van de, Laar, M. van (2008). Alcoholgebruik onder jongeren: hoe vaak en met welke gevolgen? Verslaving : Tijdschrift over Verslavingsproblematiek, 4(3), 4-15.

Laar, M. van, Dorrselaer, S. van, Monshouwer, K., Graaf, R. de (2007). Cannabisgebruikers kampen vaak met psychische stoornissen. Verslaving : Tijdschrift over Verslavingsproblematiek, 3(2), 3-14.

Laar, M. van, Dorsselaer, S. van, Monshouwer, K., Graaf, R. de (2007). Does cannabis use predict the first incidence of mood and anxiety disorders in the adult population? Addiction, 102, 1251–1260.