Pubdate: Wed, 16 Jul 1997 Source: Orange County Register (CA) Author: Keith Stroup Your recent story on a supposed link between marijuana and heroin ["Marijuana found to act as a 'gateway' to other drugs," news,June 27] seriously distorts the facts of the case. While it is true that scientists have found some similarities in the effect of these two substances on portions of the brain, it must be noted that the same researchers found the same effect with nicotine and alcohol. Yet no one is suggesting that smoking cigarettes or drinking wine leads to heroin addiction. As Dr. Lester Grinspoon Of Harvard points out, the effect noted in these studies may well be part of the neurochemistry of a general pleasure response. "If you hit a home run in baseball, the same pathway is probably activated," he suggests. One cannot help but conclude that legitimate scientific research is being twisted to fit the politically correct demand of our government's insatiable "war on drugs." These new studies, while they may add to our understanding of the neurophysiology of cannabis, cannot be used to justify the misguided policy of equating marijuana with heroin under federal law, a policy that condemns tens of thousands of American to prison each year, and hundreds of thousands to arrest. Keith Stroup Washington, D.C.