Eighteen per cent of Cambridge high school students have smoked marijuana, according to a report released two days ago by the Cambridge School Committee.

"Not true-at least for last year," was the response of Karen Spinos, a student at Cambridge High and Latin. "This year, things have sort of died down, but last year the figure may have approached 50 per cent." Spinos is cochairman of a committee to revise the questionnaire.

The study was carried out in May, 1969, by a team of Harvard Med School students and physicians from the Cambridge Health Department. Two hundred and seventy-four students from Rindge Technical High and Cambridge High and Latin were questioned in randomly chosen classes.

"A Harvard graduate student would go into the class, the teacher would leave the room, and the grad student would explain the process." said Albert Giroux, a member of the Cambridge School Committee and Public Relations. Director for the school system. "First they would discuss how many students they thought were using drugs, and then the students would indicate by anonymous ballot whether they personally had tried drugs or not," he said.

According to the report, "in classroom discussions, students felt that upward of 50 to 75 per cent of their classmates had used marijuana." When ballots were counted. however. only 18 per cent admitted to having smoked grass one or more times. "The use of other stimulants, depressants, or drug derivatives was insignificant," the report added. "Only three of the 274 students polled claimed they had used LSD."

Charles H. Cremens, Director of Health and Safety Education in Cambridge schools, said the study was used "in developing courses to recommend to the School Department."

"We are recommending establishment of an adolescent clinic at Cambridge City Hospital," he added.