In an interview on Medicinal Marijuana

Which is Marijuana the Forbidden Medicine. 

This is a more medical book. Dr Grinspoon is a psychiatrist and he initially approached the whole subject of medicinal cannabis with a rather unfavourable outlook. He was meant to be writing a report for the US government on the effects of cannabis but, as he himself says, the more he delved into the subject the more he realised that the presumed harmfulness of cannabis had been exaggerated for political reasons, and he found cannabis to have a series of positive effects on health. So he started to gather information from patients, which formed the basis of this book. 

Moving beyond this book for the moment, if we look at the scientific evidence on the subject, there is growing proof in favour of medicinal cannabis. If you look at the potential negative side effects, they are negligible compared to the side effects of the majority of more traditional (allopathic) medicines. The first book I mention and, in part, the second book too, could be considered part of a counter-cultural movement, but my third book marked the moment when the issue became a serious scientific and medical debate – it entered the mainstream, so to speak.