Smoking cannabis ages the brain by an average of 2.8 years, new research suggests. This is compared to four years in schizophrenia patients, according to the largest study of its kind. Brain ageing is defined as reduced blood flow through the organ. Excessive alcohol also ages the organ by 0.6 years, the research adds. Lead author Dr Daniel Amen, founder of Amen Clinics, said: 'The cannabis abuse finding was especially important, as our culture is starting to see marijuana as an innocuous substance. This study should give us pause about it.' Reduced brain blood flow has previously been linked to...