Rather than getting into the cultural or media criticism of the Frum-Riggs-Frum-Sullivan fracas over cannabis policy, perhaps it makes more sense to try to separate out the knowns and identify the unknowns. Experts on the question see open questions where passionate amateurs are most dogmatic about the answers.
1. Cannabis dependency is rarely as bad as severe alcoholism, but it can be plenty bad enough, and it isn’t very rare, especially among those who start – as most users now do – in their middle teens. (A sixteeen-year-old who goes beyond experimentation has about one chance in six of winding up a heavy daily user for a period of months or years.)
2. Most users – and even many frequent users – don’t go on to diagnosable abuse or dependency. There is little evidence of lasting damage from use that isn’t both heavy and chronic. It would be a mistake to attribute all of the suffering of even the heavy, chronic users to cannabis, as opposed to the social circumstances and personal traits that lead them to acquire and maintain the habit. But it would be equally a mistake to ignore their self-reports that cannabis is a source of trouble in their lives.
3. For the non-abusing majority of users, cannabis is a fairly harmless pleasure. For some of them, cannabis use lastingly enhances their lives by broadening their range of experience, deepening their appreciation of the arts, and enhancing their creativity by teaching them a new way of thinking. Very little is known about these phenomena in any systematic way, partly because the science is hard and partly because of the constraints and incentives that influence research.