Schizophrenics three times more likely to consume cannabis, says study

People with schizophrenia are three times more likely to consume cannabis than those without the disorder. This is one of the main conclusions of an international study, which saw the participation of both professionals and patients at Barcelona's Vall d'Hebron hospital.

The study, published in the magazine 'Nature Neuroscience,' involved samples from 184,765 patients and reveals 16 new genetic regions showing a lifetime predisposition to consume cannabis.

Some 24% of the genetic base making people susceptible to the consumption of cannabis overlaps with the genetic base of schizophrenia.

One of the main researchers from the group studying mental health and addiction at the Vall d'Hebron Research Institute (VHIR), doctor Marta Ribasés, said that the study raised the number of regions known to be involved from two to 16, which "is an important step forward."

The study also shows a correlation between the vulnerability to cannabis consumption over a lifetime, and the use of alcohol or tobacco, with attention-deficit hyperactivity disorder (ADHD).

Doctor Josep Antoni Ramos-Quiroga from the VHIR said the findings "will help to better understand" the relationship between the use of cannabis and mental pathologies, and will, therefore, allow for the development of individualized treatments.