Dr. Sanjay Gupta examines the potential benefits of medical marijuana. Over the last 10 years, Dr. Gupta's reporting on the topic has produced seven CNN documentaries. In his most recent investigation, he meets scientists and families who found success using marijuana for patients suffering with dementia. This special report originally aired on CNN on August 6, 2023.To learn more about how CNN protects listener privacy, visit cnn.com/privacy