Consumo de cannabis aumenta o risco de esquizofrenia?

Cannabis sativa

Nota do blog: Para o médico entrevistado no Programa Bom Dia, da Rede Globo (postada neste blog), é resposta é afirmativa. Há controvérsias. Leia a tradução do primeiro parágrafo abaixo: "De acordo com pesquisa de cientistas na Universidade de Keele Staffordshire, Reino Unido, a incidência de esquizofrenia entre os anos de 1996 e 2005 não sustentam a hipótese que o consumo de cannabis aumenta o risco para o desenvolvimento de esquizofrenia ou psicose. Para este estudo foram conduzidas análises em 186 localidades (?) na Inglaterra, País de Gales, Escócia e Irlanda do Norte. O estudo pate de uma amostra composta por quase 600.000 pacientes em cada ano, representando aproximadamente 2,3 por cento da população do Reino Unido com idades entre 16 a 44. Entre 1996 e 2005, a incidência de esquizofrenia e psicoses ou eram estáveis ou em declínio." Leiam o resto abaixo.

A dica foi enviada pelo sociólogo Dênis Petuco. Você pode ler os artigos de Dênis Petuco em www.denispetuco.com.br

Cannabis & schizophrenia

EURODRUG - INFORMATION LIST OF THE EUROPEAN COALITION FOR JUST AND EFFECTIVE DRUG POLICIES

From the IACM-Bulletin of 5 July 2009

Science: The development of the number of new schizophrenia cases in the UK does not support the hypothesis that cannabis use increases schizophrenia risk

According to research of scientists at Keele University in Staffordshire, UK, the incidence (the number of new diagnosed cases) of schizophrenia in the years 1996 to 2005 does not support the hypothesis that cannabis use increases the risk for the development of schizophrenia or psychosis. For this study an analysis of data from 183 practices in England, Wales, Scotland and Northern Ireland was conducted. The study cohort comprised almost 600,000 patients each year, representing approximately 2.3 per cent of the UK population aged 16 to 44. Between 1996 and 2005 the incidence of schizophrenia and psychoses were either stable or declining.

A recently published study found that cannabis use increased fourfold between 1972 and 2002 and 18-fold among people under 18 years of age. If the risk of schizophrenia is elevated 1.8-fold among light users and 3.1-fold among heavy users as suggested by another study, and assuming an elevated risk for 20 years, an increase in schizophrenia incidence of 29 per cent would have been expected between 1996 and 2005. Researches concluded that "the causal models linking cannabis with schizophrenia/psychoses are not supported by this study" and that "the underlying causes of schizophrenia/psychoses remained stable/declined over the study period."

(Source: Frisher M, Crome I, Martino O, Croft P. Assessing the impact of cannabis use on trends in diagnosed schizophrenia in the United Kingdom from 1996 to 2005. Schizophr Res. 2009 Jun 26. [Electronic publication ahead of print])