New research from King’s College London (KCL) and the University of Bath shows that cannabis users can be more susceptible to paranoia. In 2022, KCL launched the largest study into causes, patterns, and effects of cannabis use – Cannabis&Me – headed by Dr Marta Di Forti and funded by the Medical Research Council. Paranoid Thoughts Scale (developed in 2007, and widely used to assess paranoid thinking in patients). Cannabis is the most widely used drug in England and Wales, with 14% of 16- to 24-year-olds using. Two papers published in August 2025 show that the Cannabis&Me study has proven that “Childhood trauma was strongly associated with paranoia” and “Cannabis use significantly predicted paranoia”.