Over 2,000 studies on the effects of LSD were carried out between 1943 and
1963. Jospe says: "The relationship between such drugs and what happens
when placebos are administered in their place makes for interesting reading
and points out some thought provoking results . . ."
33 volunteers were told they were being tested as to the effects of LSD,
but were given tap water instead (Abramson, 1955). The symptoms of 25-60%
of the sample corresponded in some ways to what would have been expected if
they had taken LSD, though only 5% answered positively to such questions as
"Are things moving around you?"
In another trial (Zegans 1970) the effect of LSD on creativity was tested.
Some subjects were given LSD, others water. No differences were observed.
However, it is pointed out that the subjects may not have been creative
people in the first place.
A trial using male actors (Linton 1962) found that placebo subjects
experienced maximum loss of control after 30 minutes, and this declined
gradually. "After two hours, subjects reported feelings of having acquired
new meanings and a more prominent general feeling of disinhibition." The
researchers found that those who had taken placebos experienced similar
types of symptoms at 2, 5 and 8 hours after ingestion, although the
symptoms varied from strong to very weak.
With marijuana, some placebos were made by extracting varying amounts of
the active ingredient THC. The symptoms reported by most subjects were
consistent with strength, but the unexpected result was that chronic users
felt stronger reactions from the placebo.