December 16, 1968

Mr. Tim Douglas

Managing Editor

Ladera "3B"

La Cuesta High School

321 Ladera Street

Santa Barbara, California 98}01

Dear Mr. Douglas:

This in further response to your letter of November 5 requesting an opinion
on genetic effects of LSD.

I am enclosing one of my recent articles that summarizes my own evaluation
of the present situation. It is not very satisfactory, since there are
many uncertainties that can only be cleared up by difficult and continued
studies.

One should be careful to state exactly what the question is. If you were to

ask whether there were scientifically rigorous and irrefutable proof that

LSD caused genetic or embryological abnormalities in man, I would have to say
that the evidence does not yet meet that standard. If you were to ask me

for reassurance about the safety of LSD from the point of view of its gametic
hazard, I would have to say that the existing evidence points to grave doubts
about that safety.

There are very serious obstacles in the way of getting easy answers to ques~
tions of this kind. It is very difficult to find people with an established
history of chronic use of LSD who have not also exposed themselves to many
other drugs and habits of life ¢haoor nutrition and exposure to virus infec-
tions - that might play at least an important a role in genetic or fetal
damage. This criticism is particularly applicable to the kind of report that
was, for example, recently publicized from Dr. Jacobson's work, of which I
enclose a newspaper clipping.

The fact still remains thatLSD has been found to have effects on cells in
tissue culture and that the best studies that have been published so far
do point to a considerable increase in the frequency of cells with broken
chromosomes among chronic LSD users. Other drugs in high dosage may well
Mr. Tim Douglas December 16, 1968
Page 2

cause similar effects, and the whole area ig one that deserves much more
detailed investigation. Meanwhile, albBhough I would have to discount some
of the scarier and more alarming reports, I would have to caution that there
are grave doubts about the health hazards of LSD on several counts, and we
cannot ignore the possibility of genetic damage from its chronic use.

Sincerely yours,

Joshua Lederberg
Professor of Genetics