Teenagers who smoke cannabis weekly or more are twice as likely as non-users to have an anxiety disorder in their late 20s, even if they stop using, a study of 2000 Victorian teenagers has found. Although this raises a question of correlation versus causation, such as whether cannabis use causes/exacerbates later anxiety or whether people with anxiety disorders are more prone to use anxiety.
Read more at: http://medicalxpress.com/news/2012-08-heavy-teenage-cannabis-linked-anxiety.html#jCp
