New Canadian research shows a connection between heavy cannabis use and dementia, heart attacks, schizophrenia and even death

A study of adolescent twins links occasional cannabis use with increased psychotic-like experiences. The findings suggest the relationship is shaped by individual environments rather than shared genetics or specific brain connectivity patterns.

A study of over 500,000 Americans suggests that substances like PCP and cannabis consistently predict higher arrest rates. Conversely, psilocybin is associated with lower odds of offending, though these protective effects vary by race and age.