Laura S Daedelow1, Tobias Banaschewski2, Moritz Berning3, Arun L W Bokde4, Rüdiger Brühl5, Erin Burke Quinlan6, H Valerie Curran7, Sylvane Desrivières6, Herta Flor8, Antoine Grigis9, Hugh Garavan10, Anita Hardon3, Jakob Kaminski11, Jean-Luc Martinot12, Marie-Laure Paillère Martinot13, Eric Artiges14, Hayley Murray3, Frauke Nees15, Nicole Y L Oei16, Dimitri Papadopoulos Orfanos9, Tomáš Paus17, Luise Poustka18, Sarah Hohmann2, Sabina Millenet2, Annika Rosenthal11, Juliane H Fröhner19, Michael N Smolka19, Henrik Walter11, Robert Whelan20, Reinout W Wiers21, Gunter Schumann22, Andreas Heinz11. 1. Department of Psychiatry and Psychotherapy CCM, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany. Electronic address: laura.daedelow@charite.de. 2. Department of Child and Adolescent Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Square J5, 68159 Mannheim, Germany. 3. Amsterdam Institute for Social Science Research, University of Amsterdam, Amsterdam, the Netherlands. 4. Discipline of Psychiatry, School of Medicine and Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland. 5. Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany. 6. Centre for Population Neuroscience and Precision Medicine (PONS), Institute of Psychiatry, Psychology & Neuroscience, SGDP Centre, King's College London, United Kingdom. 7. Clinical Psychopharmacology Unit, University College London, London, United Kingdom. 8. Institute of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Square J5, Mannheim, Germany; Department of Psychology, School of Social Sciences, University of Mannheim, 68131 Mannheim, Germany. 9. NeuroSpin, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France. 10. Departments of Psychiatry and Psychology, University of Vermont, 05405 Burlington, VT, USA. 11. Department of Psychiatry and Psychotherapy CCM, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany. 12. Institut National de la Santé et de la Recherche Médicale, INSERM U A10 "Trajectoires développementales en psychiatrie"; Université Paris-Saclay, Ecole Normale supérieure Paris-Saclay, CNRS, Centre Borelli, Gif-sur-Yvette, France. 13. Institut National de la Santé et de la Recherche Médicale, INSERM U A10 "Trajectoires développementales en psychiatrie"; Université Paris-Saclay, Ecole Normale supérieure Paris-Saclay, CNRS, Centre Borelli; and AP-HP.Sorbonne Université, Department of Child and Adolescent Psychiatry, Pitié-Salpêtrière Hospital, Paris, France. 14. Institut National de la Santé et de la Recherche Médicale, INSERM U A10 "Trajectoires développementales en psychiatrie"; Université Paris-Saclay, Ecole Normale supérieure Paris-Saclay, CNRS, Centre Borelli; and Psychiatry Department 91G16, Orsay Hospital, France. 15. Department of Child and Adolescent Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Square J5, 68159 Mannheim, Germany; Institute of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Square J5, Mannheim, Germany; Institute of Medical Psychology and Medical Sociology, University Medical Center Schleswig Holstein, Kiel University, Kiel, Germany. 16. Research Priority Area (RPA) Yield, University of Amsterdam, Amsterdam, the Netherlands; Developmental Psychology (Addiction Development and Psychopathology ADAPT-lab), University of Amsterdam, Amsterdam, the Netherlands; Amsterdam Brain and Cognition (ABC), University of Amsterdam, Amsterdam, the Netherlands. 17. Bloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, Departments of Psychology and Psychiatry, University of Toronto, Toronto, Ontario M6A 2E1, Canada. 18. Department of Child and Adolescent Psychiatry and Psychotherapy, University Medical Centre Göttingen, von-Siebold-Str. 5, 37075 Göttingen, Germany. 19. Department of Psychiatry and Neuroimaging Center, Technische Universität Dresden, Dresden, Germany. 20. School of Psychology, Global Brain Health Institute, Trinity College Dublin, Ireland. 21. Department of Developmental Psychology, Adapt Lab, Research Priority Area Yield, University of Amsterdam, Nieuwe Achtergracht 129-B, 1018 WS Amsterdam, the Netherlands. 22. Centre for Population Neuroscience and Precision Medicine (PONS), Institute of Psychiatry, Psychology & Neuroscience, SGDP Centre, King's College London, United Kingdom; PONS Research Group, Dept of Psychiatry and Psychotherapy, Campus Charite Mitte, Humboldt University, Berlin and Leibniz Institute for Neurobiology, Magdeburg, Germany, and Institute for Science and Technology of Brain-inspired Intelligence (ISTBI), Fudan University, Shanghai, PR China.
Abstract
OBJECTIVE: To assess changes in cannabis use in young adults as a function of psychotic-like experiences. METHOD: Participants were initially recruited at age 14 in high schools for the longitudinal IMAGEN study. All measures presented here were assessed at follow-ups at age 19 and at age 22, respectively. Perceived stress was only assessed once at age 22. Ever users of cannabis (N = 552) gave qualitative and quantitative information on cannabis use and psychotic-like experiences using the Community Assessment of Psychic Experiences (CAPE). Of those, nearly all n = 549 reported to have experienced at least one psychotic experience of any form at age 19. RESULTS: Mean cannabis use increased from age 19 to 22 and age of first use of cannabis was positively associated with a change in cannabis use between the two time points. Change in cannabis use was not significantly associated with psychotic-like experiences at age 19 or 22. In exploratory analysis, we observed a positive association between perceived stress and the experience of psychotic experiences at age 22. CONCLUSION: Age of first use of cannabis influenced trajectories of young cannabis users with later onset leading to higher increase, whereas the frequency of psychotic-like experiences was not associated with a change in cannabis use. The observed association between perceived stress and psychotic-like experiences at age 22 emphasizes the importance of stress experiences in developing psychosis independent of cannabis use.
OBJECTIVE: To assess changes in cannabis use in young adults as a function of psychotic-like experiences. METHOD: Participants were initially recruited at age 14 in high schools for the longitudinal IMAGEN study. All measures presented here were assessed at follow-ups at age 19 and at age 22, respectively. Perceived stress was only assessed once at age 22. Ever users of cannabis (N = 552) gave qualitative and quantitative information on cannabis use and psychotic-like experiences using the Community Assessment of Psychic Experiences (CAPE). Of those, nearly all n = 549 reported to have experienced at least one psychotic experience of any form at age 19. RESULTS: Mean cannabis use increased from age 19 to 22 and age of first use of cannabis was positively associated with a change in cannabis use between the two time points. Change in cannabis use was not significantly associated with psychotic-like experiences at age 19 or 22. In exploratory analysis, we observed a positive association between perceived stress and the experience of psychotic experiences at age 22. CONCLUSION: Age of first use of cannabis influenced trajectories of young cannabis users with later onset leading to higher increase, whereas the frequency of psychotic-like experiences was not associated with a change in cannabis use. The observed association between perceived stress and psychotic-like experiences at age 22 emphasizes the importance of stress experiences in developing psychosis independent of cannabis use.