A new study, published in the journal Schizophrenia Research, adds to the growing evidence that marijuana may be helpful to some who suffer from attention deficit hyperactivity disorder, or ADHD. The study also sheds light on the ongoing controversy over marijuana's relationship to schizophrenia.
Researchers looked at three groups of young people, age 14-21 -- non-psychotic siblings of schizophrenia patients (considered at "genetic risk" for psychosis), adolescents with ADHD, and healthy controls -- and compared the marijuana users with non-users in each group on a variety of psychological tests. There was a correlation between signs of mental health disturbance and marijuana use for the group of siblings at genetic risk for psychosis, but not for the other groups. This suggests that marijuana may worsen the prognosis of those with a predisposition to psychosis but does not make healthy people psychotic.
In the ADHD group, the results suggested marijuana may be beneficial: In several of the tests, there was a trend toward better functioning among the marijuana using ADHD patients than among the non-users. In the article, the researchers discuss a possible mechanism by which marijuana "could attenuate some of the behavioral symptoms of ADHD." This is an area that cries out for more research.