The Effects of Marijuana

Practically everybody, whether doctor or layman, pothead or puritan, has been expressing dogmatic opinions for years about the effects of marijuana on its users. It therefore came as a surprise last week when a team of Harvard and Boston University investigators reported that they had just conducted the first truly scientific tests ever made on the subject. Their findings, which appear in Science magazine, confirm some popular ideas about marijuana's effects and expose others as completely false. The drug, the investigators concluded, "appears to be...