Pot smoking may increase the risk for depression in teens who are already susceptible to the disorder, according to a new study.
About two-thirds of the popular have a variant of the serotonin gene that increases depression vulnerability, said the researchers at Radboud University Nijmegen in the Netherlands. When data were collected from 428 families containing two teenage children each, a strong association was found between marijuana use and depression symptoms in the teens having this particular gene variant.
Even when other factors were taken into account, such as smoking, alcohol use, upbringing, personality and socioeconomic status, the link remained strong.
"Some people might think that young people with a disposition for depression would start smoking cannabis as a form of self-medication," said the authors, "and that the presence of depressive symptoms is therefore the cause of cannabis use. However, in the longer term that is definitely not the case. Although the immediate effect of cannabis may be pleasant and cause a feeling of euphoria, in the longer term we observe that cannabis use leads to an increase in depressive symptoms in young people with this specific geneotype."
The study was published online in the journal Addiction Biology.