Medical School's Marijuana Study Reports Possible Physical Damage

Smoking marijuana may cause cumulative physical damage, suggested the report of a Harvard Medical School study published yesterday in Science magazine.

The study, headed by Dr. Norman E. Zinburg, assistant clinical professor of Psychiatry, marks the first time that non-marijuana smokers have been observed in a clinical laboratory as they first smoke the drug. Working with Dr. Zinberg on the project were Dr. Andrew T. Weil, a Harvard Medical School graduate and intern at Zion Hospital in San Francisco, and Judith M. Nelson, senior graduate student in pharmacology at the Boston University School of Medicine.

The overt effects of the drug are transient, according to the study--the smoker reaches a high within 15 minutes and shows no effects from the drug three hours later.

Big Bang Theory

"Yet the second time around a person gets more of a bang," explained Dr. Peter H. Knapp of Boston Medical School, in whose laboratories the study was conducted. "Is it because the smoker has learned to let go," he continued, "or is it that the drug is piling up in the nervous system? If so, it might cause physiological damage."

Dr. Knapp would not say whether the study had been run at Boston University instead of Harvard because of difficulties in gaining the Administration's sanction. "Suffice it to say," Dr. Knapp said, "that there were perfect working facilities at B.U."

The report listed several differences between the effects of marijuana and alcohol:

* Chronic smokers appear to think more clearly under influence than do new smokers, unlike chronic alcoholics.

* Marijuana smokers are less likely to overrate their performance abilities while under influence, unlike persons given a false sense of skill by alcohol.

* Chronic users are probably less dangerous highway drivers than are chronic drinkers.

The researchers qualified the conclusions of their study. It is unknown, they wrote, how intense a dose is typically taken in illegal circumstances. Nor could they tell how their subjects' expectations influenced the drug's psychological effects.