LETTER TO NIMH ADDICTION RESEARCH CENTER RE LSD EXPERIMENTS

• Document Type: SPECIALCOLLECTION
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): 00153390
• Release Decision: RIPPUB
• Original Classification: U
• Document Page Count: 2
• Document Creation Date: January 21, 2025
• Document Release Date: January 15, 1983
• Publication Date: September 16, 1953

. 1111*PLIING. AOCHINSVI Try It
geotoki.4ornttiroi
PUBLIC 14EALTR SERVICE HOSPITIL
NIMH Addict ion Research Center
� HEALTH. EDUCATION, AND VvELF/ Alh
PUBLIC HEALTH SERVICE
LEXINGTON. KENTUCKY
- to September 1953
-
You may be. interested in the progress of our i-xperiments
. with LSD to date. Originally we had planned to determine
the threshold dose for each pattenLindividually, and this
was attempted'-early in August, using a supply of LSD which
was more thantwo years old.
Negative subjective reports were obtained with doses of
20 to 70 micrograms. Finally, patients were given 100 micro�
-
crams in divIded doses, with marked subjective effects (as
well as objeetivet appearing in all 5 patients. We then
attempted to titrate-the efTecfs in each patient, giving
doses of 80 to 90 mtcrocrams. Very little effect was observed.
These doses were administered on the day following the 1CO micro-
gram dose. These doses were raised progressively until 120.tc
130 micrograms were being given to A of the subjects and
90 micrograms to the other, without any significant effects
of any kind. It was found that the time of day did not alter
the lack-of effects and, also, that a fresh supply of LSD
produced no change in the effects, or lack of them.
Since the lack of effects might be due to tolerance, adminis-
fr ation of the drug was discontinued and after five days was
agein administered, wifh merked subjective and objective
changes aloeerirg with doses of 90 to 120 micrograms. Mean-
while, tests of the drug in individuals 'who had not been
receicing it fled shown Orono Positive results. The findings
-were very suooes'leive of.rae7.,rd development of tolerance.
If :vtas, therefore, necessary fc obtain measurements affer
single doses at widely scattered intervals. As long as the
interval was as much as 3 days, there was no noticeable
_
Declasified by 4-1N-187475
data � ra z9y7
-
decrease in effect, but there may be some decrease 1n effect
if"-thedrug Is administered every third daY., �
Irhem Oveil at proper Intervals, LSD induces. very7defimite.
blood pressure rise, pOpillary dilatation, increase in deep
tendon reflexes, and diminution in superficial skin reflexes.
The puoillary-effects and blood pressure effects appear to
be suitable for measurements of tolerance..
LSD appears to facilitate synchromization of the electro�
encephalogram by photic stimulation. Photic stimulation also
seems to enhance. the perception of elementary hallucinations.
Apparently the supply of LSD is quite limited and we may be
unable to obtain sufficient amounts of the drug to carry out
the study as originally planned.- However, we believe we
have sufficient material to accomplish the following:
II Effects of larger doses in non�tolerant patients.;
2: Determination of whether tolerance occurs after one single
dose of LSO;
31 Controlled -studies of toterance development in 5 patients;
41 Compartson of LSDwith LAE.
Stncere y yours,
Harris Isbell, M.D.
Director of Research
Declassified by e:87475
date
�