A ground-breaking study of 4117 marijuana smokers in California1 reveals that the 'Gateway Theory' probably had it backwards. Instead of enticing young people to use other drugs, this study suggests that marijuana may have the opposite effect. This first-ever clinical examination of a large number of medical marijuana applicants depicts a population that is remarkably normal. The percentages earning bachelors' degrees and doctorates are nearly identical to the national numbers. They are, in the main, productive citizens with jobs, homes and families who smoke marijuana weekly or daily – and have in some cases for decades. For the vast majority of these applicants, their use of cannabis ultimately led to a decrease in the use of tobacco, alcohol, and hard drugs. Asked to compare their current alcohol consumption with their lifetime peak, over 10% claimed to be abstinent and nearly 90% claimed to have cut their drinking in half. They also report using cannabis as self medication for stress and anxiety – with fewer side effects than the legal pharmaceutical alternatives. As children, a significant percentage of the male applicants had been treated for ADHD (Attention Deficit Hyperactivity Disorder). Today their routine morning use of minimal amounts of cannabis strongly suggests that it enhances their ability to concentrate by allowing them to focus on one problem at a time. As one construction company estimator said, "After two hits and my morning coffee, I'm the best estimator in the company."