After its re-introduction in the 1960s, cannabis has become the most widely used illicit drug in Europe. Along with the spread of cannabis use, its social meaning has changed over time. Today old paradigms are having renewed appeal, in particular on the subject of cannabis and schizophrenia. Cannabis in Europe is about trends in the scientific study on cannabis, changing national policies and changing cannabis markets. Recent years show a strong tendency towards market substitution: from hashish imported from other parts of the world to domestically grown marihuana. Who are these marihuana growers? How do national policies respond to this new phenomenon? Why has cannabis policy become liberal in some countries, while in others it develops in a more repressive direction? In this book, scientists from various European countries present a rich insight into similarities and differences between national cannabis markets, and critically discuss policies and police, treatment and prevention practices.