This government document details a planned but ultimately unsuccessful research study called CANTOP-RCT, which aimed to investigate **cannabidiol (CBD)** as a treatment for individuals at **high clinical risk of developing psychosis**. The study was designed as a **double-blind, placebo-controlled randomized controlled trial** to assess CBD's effectiveness in alleviating psychotic and anxiety symptoms, its safety, and its impact on brain activity. Despite securing funding, the trial was **closed down due to persistent issues in obtaining a consistent and reliable supply of medical-grade CBD**. The authors discuss the challenges encountered, including intellectual property concerns and the impact of external factors like the COVID-19 pandemic, offering **learnings for future research** in this complex area.

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