A University of Pittsburgh Medical Center study published in the journal Psychology of Addictive Behaviors last September found that chronic marijuana use during adolescence did not lead to depression, anxiety, psychosis, or asthma by mid-life.

The U.K.’s Independent was one of many newspapers that celebrated the news, scoffing at the National Health Service help page that warns: “Your risk of developing a psychotic illness is higher if you start using cannabis in your teens.”
 
Now, however, the journal has run a correction. It turns out that the researchers misinterpreted their data. They checked it again after criticism of their study and found that there was a two-and-one-half-fold increase in psychotic disorders in midlife after chronic marijuana use that began in adolescence.
 
The director of the Maryland chapter of SAM (Smart Approaches to Marijuana) caught the error and notified the journal which lead to the correction. SAM is calling on all media who reported the original incorrect story to correct their account of it now.
 
Read Independent story here.  Read SAM account of the correction here.

Source: Email from Monte Stiles, National Families in Action, January 2016