Via Science Daily:
Young people who are genetically vulnerable to depression should be extra careful about using cannabis: smoking cannabis leads to an increased risk of developing depressive symptoms. This has emerged from research carried out by Roy Otten at the Behavioural Science Institute of Radboud University Nijmegen that is published in the online version of the scientific journal Addiction Biology. Two-thirds of the population have the gene variant that makes one sensitive to depression.
Many young people in the Netherlands use cannabis. Nearly 30% of 16-year-olds indicate that they have used cannabis on at least one occasion, and 12% that they have used it during the past month. Besides worse performances at school, the use of cannabis also increases the risk of developing schizophrenia and psychosis. Smoking hashish and weed were thought to increase the risk of depression but no conclusive evidence for this was available to date. Otten suspects that this is partly because his predecessors failed to consider the individual genetic vulnerability to depression.
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