22 de outubro de 2021

Daily Use, Especially of High-Potency Cannabis, Drives the Earlier Onset of Psychosis in Cannabis Users

27 de dezembro de 201313min18
  1. Marta Di Forti*,1,
  2. Hannah Sallis2,
  3. Fabio Allegri3,
  4. Antonella Trotta1,
  5. Laura Ferraro4,
  6. Simona A. Stilo5,
  7. Arianna Marconi1,
  8. Caterina La Cascia4,
  9. Tiago Reis Marques1,
  10. Carmine Pariante6,
  11. Paola Dazzan1,
  12. Valeria Mondelli6,
  13. Alessandra Paparelli1,
  14. Anna Kolliakou1,
  15. Diana Prata1,
  16. Fiona Gaugrhan1,
  17. Anthony S. David1,
  18. Craig Morgan5,
  19. Daniel Sthal7,
  20. Mizanur Khondoker7,
  21. James H. MacCabe1,8 and
  22. Robin M. Murray1,8

+ Author Affiliations

  1. 1 Department of Psychosis Studies, Institute of Psychiatry, Kings College London, London, UK;
  2. 2 School of Social and Community Medicine, Bristol University, Bristol, UK;
  3. 3 Department of Psychiatry, Bologna University, Bologna, Italy;
  4. 4 Department of Psychiatry and Neuroscience, Palermo University, Palermo, Italy;
  5. 5 Department of Health Services and Public Health, Institute of Psychiatry, Kings College London, London, UK;
  6. 6 Department of Psychological Medicine, Institute of Psychiatry, Kings College London, London, UK;
  7. 7 Department of Biostatistics, Institute of Psychiatry, Kings College London, London, UK
  1. 8Joint last authors.
  2. *To whom correspondence should be addressed; Department of Psychosis Studies, Institute of Psychiatry, Kings College, De Crespigny Park, London SE5 8AF, UK; tel: 0044207-8480145, fax: 0044207-8480100, e-mail: marta.diforti@kcl.ac.uk


Cannabis use is associated with an earlier age of onset of psychosis (AOP). However, the reasons for this remain debated. Methods: We applied a Cox proportional hazards model to 410 first-episode psychosis patients to investigate the association between gender, patterns of cannabis use, and AOP. Results: Patients with a history of cannabis use presented with their first episode of psychosis at a younger age (mean years = 28.2, SD = 8.0; median years = 27.1) than those who never used cannabis (mean years = 31.4, SD = 9.9; median years = 30.0; hazard ratio [HR] = 1.42; 95% CI: 1.16–1.74; P < .001). This association remained significant after controlling for gender (HR = 1.39; 95% CI: 1.11–1.68; P < .001). Those who had started cannabis at age 15 or younger had an earlier onset of psychosis (mean years = 27.0, SD = 6.2; median years = 26.9) than those who had started after 15 years (mean years = 29.1, SD = 8.5; median years = 27.8; HR = 1.40; 95% CI: 1.06–1.84; P = .050). Importantly, subjects who had been using high-potency cannabis (skunk-type) every day had the earliest onset (mean years = 25.2, SD = 6.3; median years = 24.6) compared to never users among all the groups tested (HR = 1.99; 95% CI: 1.50- 2.65; P < .0001); these daily users of high-potency cannabis had an onset an average of 6 years earlier than that of non-cannabis users. Conclusions: Daily use, especially of high-potency cannabis, drives the earlier onset of psychosis in cannabis users.  


acesse: http://schizophreniabulletin.oxfordjournals.org/content/early/2013/12/14/schbul.sbt181.abstract                

Sobre a UNIAD

A Unidade de Pesquisa em álcool e Drogas (UNIAD) foi fundada em 1994 pelo Prof. Dr. Ronaldo Laranjeira e John Dunn, recém-chegados da Inglaterra. A criação contou, na época, com o apoio do Departamento de Psiquiatria da UNIFESP. Inicialmente (1994-1996) funcionou dentro do Complexo Hospital São Paulo, com o objetivo de atender funcionários dependentes.