Anxiety (Panic)/DepressionGeneticsMarijuana (Cannabinoids)

Cannabis and the genetic vulnerability for depression

Evidence for the association between cannabis and depression is inconsistent.

Researchers at Radboud University Nijmegen, in The Netherlands, evaluated the potential influence of a person’s genetics on the cannabis/depression risk.

First, the details.

  • Data from 310 adolescents over 4 years were evaluated.
  • Each year they answered questions about their behavior and depressive symptoms.
  • The possible role of genetics (the transporter gene-linked polymorphic region [5-HTTLPR] genotype) was considered.
  • Data from the younger siblings of the adolescents were used in an attempt to replicate potential findings.

And, the results.

  • Cannabis use increases the risk for an increase in depressive symptoms over time but only in the presence of the short allele of the 5-HTTLPR genotype.

The bottom line?

The authors concluded, “In the longer term… cannabis use leads to an increase in depressive symptoms in young people with this specific genotype.”

One of the most popular areas of genetic study is the serotonin transporter-linked polymorphic region (5-HTTLPR). The short (S) allele of the 5-HTTLPR is associated with several psychiatric conditions including depression.

It appears that cannabis interacts with 5-HTTLPR and increases the risk of depression.

10/20/11 22:05 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.