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The After-Effects of Psychedelics

A Summary of Four Questionnaire Studies, 1963.

The results presented below were extracted from four studies conducted during the 1960s in which LSD or psilocybin was given to volunteer subjects. The after-effects of one experience was assessed by means of questionnaires. The studies selected were concerned only with subjective claims, not with objective ratings or indices. Studies of specific-descriptions of the content of psychedelic experiences are not included. The questionnaires were designed to reveal the subjects’ general evaluations of their experience, and the ongoing effect of these psychedelic experiences.

Subjects, methods, and background of each of the four studies will be briefly described. Only a brief discussion is given of the tables (the original papers may be consulted for more extensive evaluation). The purpose of this summary is to present these strikingly similar, and in part hitherto unpublished, data together in convenient form.[1]

​The data presented here is based on 74 questionnaires returned by subjects who had been given 100 micrograms of LSD six-months to three-and-a-half years previously. The LSD was given in "a permissive but non-treatment" setting in order to compare the LSD experience with that of delirium tremens.

The first study is described here:

“Our subjects received no intended psychotherapy during the LSD experience. In general, the atmosphere was relaxed and permissive, with the subjects well-protected from outside disturbances. They underwent the experience in a darkened room, and were allowed various sensory stimuli such as music, paintings, and exposure to sunlight in a garden setting. Usually, the LSD was given to groups of three to five subjects. At least one 'sitter' was constantly present who himself had experienced LSD.”

Half the subjects in this study were patients. In other words, they were undergoing some form of psychotherapy. The others were colleagues, psychotherapists, lawyers, writers, etc. This first study will be referred to subsequently as the Ditman Study.[2]

A questionnaire overlapping much of the questionnaire in the Ditman Study was used, and the results are presented together in Table One and Table Two. All subjects had undergone the LSD experience 3 to 14 months previously.

All 96 subjects were paying patients. Subjects were typically given 100-200 μg. of LSD plus 200-400 mg. of mescaline, individually, after intensive preparation. This preparation included discussion of aims, of willingness to surrender old concepts and preconceived ideas, and of the necessity for trust.

“All of the pre-treatment contacts aird in the development of these key factors within the subject, willingness and trust, which are essential to the movement into and most effective use of the psychedelic experiences.

The inhalation of a 30% CO₂ and 70% oxygen mixture B is also used in the preparation, which:

“...gives the subject an opportunity to 'practice' the sort of surrender which will be called for on the day of the LSD session.

The psychedelic session is held in the congenial surroundings of a tastefully furnished room containing a tape-and-record player console and various carefully chosen works of art. The subject spends a good fraction of the day lying comfortably on a couch listening to music.

The therapist will usually initiate rather little conversation during the session. The subject is ordinarily encouraged alternately to explore within, and to respond to stimuli in the outer environment (such as flowers, room furnishings, works of art, photographs of close relations, etc.)...The subject is urged to postpone analyzing his experience until after the session and to accept the experience as it occurs without labeling or evaluating.”

This study will be referred to subsequently as the Savage Study.[3]

”Of the 194 subjects 73 were undergoing psychotherapy and took LSD an average of 3.6 times as a therapeutic aid. The remaining 121 subjects were volunteers and averages 1.9 sessions. The average interval between the administration of LSD and the completion of the questionnaire was 10 months and the average maximum dosage 171 μg.

The non-therapy groups contained twenty physicians, seven psychologists, one dentist; artists, writers, musicians, ministers; teachers, engineers, housewives, secretaries, students and others.

"The conditions under which LSD was administered varied somewhat. The therapy group was made up of patients under several psychotherapists and the conduct of the session depended on their orientation. It should be mentioned that for some of this group, LSD was somewhat incidental to their overall treatment and the results are perhaps not comparable to those of patients for whom drug treatment played a major role. The artists participated in a creativity study in which they were asked to paint specific objects while under the effects of LSD. The other non-therapy subjects were generally left undisturbed, and wrote a subjective report the following day.

This study will be referred to subsequently as the Janiger Study.[4]

​The data presented are based on questionnaires returned by 98 subjects, one day to three weeks after they had been given psilocybin. Occupationally, the subjects included graduate students, professional writers and artists, psychologists, musicians, housewives and inmates in a correctional institution. They were given doses of psilocybin ranging from 4 mg to 100 mg, with a medium dose of 16 mg.

The drug was given in all comfortable home-like surroundings, with no medical or experimental procedures introduced during the session. Subjects were given all available information on the drug and were allowed to regulate their own dosage, within a maximum set by the experimenter. Subjects were free to explore whatever aspects of an experience they wished.”

Preliminary discussions and reading were designed to prepare the subjects for a pleasant experience involving insight and expanded awareness. Therapy was not attempted during the session, although the inmate subsample were involved in an experimental behavior-change program and therefore expected change. Music, art, pictures, etc., were available during sessions, which were held in small groups ranging from 3 to 10 participants. A ‘guide’ who had experienced psilocybin previously was always present. This study will be referred to subsequently as the Leary Study.[5]

Table One: The Experience
Study participants were asked the question: "Looking back on your LSD experience, how does it look to you now?" The percentages listed in the table below are responses in the first two of the following four categories: "Quite a bit," "Very much," "A little," "Not at all."

Response Ditman (N=74) Savage (N=96)
A very pleasant experience 72 85
Something I want to try again 66 89
An experience of great beauty 66 81
Greater awareness of reality 64 92
Feel it was of lasting benefit 50 85
The greatest thing ever 49 78
A religious experience 32 83
A very unpleasant experience 19 33
A disappointing experience 7 1
An experience of insanity 7 18
Did me harm mentally 1 1
Like travelling to a far-off land 39
Very much like being drunk 32
A return to feelings of childhood 28
Discomfort and illness 17

Table Two: The After-effects
Study participants were asked: "How were you, or what were you left with, after your LSD experience?" The percentages listed in the table below are the responses in the first two of the following four categories: "Quite a bit," "Very much," "A little," "Not at all."

Response Ditman (N=74) Savage (N=96)
A new way of looking at the world 48 85
A greater understanding of the importance and meaning of human relationships 47 86
A new understanding of beauty and art 43 64
A greater awareness of God, or a Higher Power, or an Ultimate Reality 40 90
A sense of greater regard for the welfare and comfort of other human beings 38 78
A realization that I need psychotherapy 17 26
A religious experience 32 83
More ability to relax and be myself 40 74
Improvement noted by person closest to me 42 64
Greater tolerance of others 40 75
Did me harm mentally 1 1
A sense of futility and emptiness 7 8
A frightening feeling that I might go crazy or lose control of myself 3 8
A sense of relaxation and freedom from anxiety and tension 56
A better understanding of the cause and source of my troubles 41
A set of new decisions and new directions for my life 39
A new sense of fun and enjoyment 39
A sense of now knowing what life is all about 27

Table Three: Later Improvements
Principal areas of claimed improvement attributed to LSD

Response Ditman (N=74)
More ability to relax 48
More comfort with people 37
More initiative since LSD 36
Less anxiety 34
Increased interest in Nature 38
Increased interest in Art 34
Increased interest in Music 33
Deeper significance to things 46
Things seem more real 40
Problems less important 39
Colors appear brighter 39
I am more tolerant 40
More accepting of ideas 36
More broadminded 37
Less irritable 33
Changes in sense of values 47
Emotional / financial / drinking / legal problems improved 33
Improvement in income, living quarters, and body weight 15
Increased sex satisfaction 14

Table Four: Personal changes
Changes attributed to LSD - Janiger

Response Janiger (N=194)
Major objective changes (in job, marital status, etc.) 16
Positive change in relationships:
with co-workers and employees 43
with acquaintances 41
Increased interest in:
social reform 18
political and international affairs 32
anthropology 24
morals and ethics 35
Other universal concepts (meaning of life) 48
Positive change noticed by person closest 45
Change in sense of values: money, status, relationships, religion etc 48
Looking back on the LSD trip, it was:
a very pleasant experience 32
something I would want to try again 74
a religious experience 24
an experience giving greater understanding of myself and others 61
an experience of lasting benefit 58
LSD should be used for:
becoming aware of oneself 75
gaining new meaning to life 58
helping to understand other people 42

Table Five: Subjective Reactions
Subjective reactions to psilocybin - Leary Study

Response Leary (N=98)
How supportive (relaxing, warm, accepting) was the situation?
Very supportive 56
Mildly supportive 22
Mildly or very rejecting 11
Was the experience pleasant?
Wonderful or ecstatic 32
Very pleasant 38
O.K. 23
Unpleasant or very unpleasant 7
Did you learn a lot about yourself and the world?
Tremendous insights 23
Learned a lot 22
Learned something of value 43
Learned nothing 9
More confused 2
Has the mushroom experience changed you and your life?
Dramatically better 12
Changed for better 50
No change 37
Worse 1
How about taking the mushroom again under tasteful, secure circumstances?
Very eager 56
Like to 34
Don't care 6
Rather not 4


Table One shows that in both the Ditman and Savage studies, a majority of the subjects claim that the experience was pleasant and gave them increased awareness. 50% in the Ditman study and 85% in the Savage study report lasting benefit. The higher figures in the Savage study are probably attributable to the more intensive preparations and to the conduct of sessions centered on the individual subject. The percentage of experiences reported to be harmful or unpleasant is very small in both studies.

Table Two reviews some of the descriptions which subjects consider appropriate to their LSD experience. "Greater understanding of interpersonal relationships" and "a new way of looking at the world" are frequent in both samples. In the Savage study, "awareness of God or a Higher Power or an Ultimate Reality" is the most frequent item, and this is significantly correlated (r = 68) with reports of lasting benefit. In the Ditman study:

"...those who had a religious orientation, particularly those with a mystical orientation, claimed the most benefit from the experience and found it the most pleasant."

These results suggest that perhaps something akin to a religious conversion experience is taking place in some of the subjects.

Table Three lists the principal area of improvement attributed to LSD in the Ditman study.

Table Four gives comparable figures from the Janiger study; most frequently reported changes occurred in interpersonal relations and in values. 75% of all the subjects in this study indicated LSD should be used for increasing self-awareness.

Table Five gives the results of the Leary study: 70% find the experience pleasant, 88% learn something from it, 62% report that it changed their life, and 90% want to try it again.

​On some of the questions it is possible to collate the results from all four studies. Thus the percentages reporting a pleasant experience in the four studies are 72, 85, 66 and 70, or an average of 73%. Percentages reporting lasting benefit or change are 50, 85, 58 and 62, or an average of 64%. Percentages wishing to repeat the experience are 66, 89, 74, and 90, or an average of 80%.

​In three of the studies, an attempt was made to evaluate the longevity of these claims. In other words: to what extent they are maintained after longer periods of time. In the Savage study, answers were compared at four time periods: less than three months after the LSD session; three to six months; six to twelve months; and over twelve months. The results indicated thatL

"...felt benefit tends to become apparent some time after the LSD experience and to be sustained fairly well over at least the first year following."

In the Janiger study, results were compared after: 0-100 days; 100-389 days; and more than 389 days. Results indicated that:

"...there is a definite decrease in claimed effect as a function of time, and that the decrement is sharpest during the first six months or so. Of individual questions, "becoming aware of self," changes in values, and claims of "lasting benefit" seem to be fairly resistant to erosion by time."

In the Ditman study 16 alcoholic patients returned a second questionnaire, approximately three and one-half years after their original LSD experience. They "made fewer claims than they had on the first questionnaire. About two-thirds still claimed periods of abstinence ranging from one to one and one-half years, as they had on the first questionnaire, and three-fourths of these alcoholics still claimed some lasting benefit (fewer arrests, increased self-understanding and aesthetic interest). None of the group, however, had maintained their sobriety to the time of the second questionnaire.

It should be remembered that these four studies are all reports of subjective claims and need to be supplemented by studies of changes in objective behavioral indices. Furthermore, in general, these positive results do not agree with the majority of studies of psychedelic drugs in the psychiatric literature.

There are two kinds of studies of drug-effects: those in which observations and evaluations are made by the researcher-psychiatrist, and those in which the subject records his own impressions and observations. The first kind of study rends on the whole to lead to negative evaluation—the substances are seen as 'psychotomimetic,' producing 'depersonalization,' space-time 'distortions,' etc.

When subjects describe their own experiences, they use phrases such as "awareness of higher reality," "transcendence or time and space," of what may essentially be similar subjective effects. It is important to keep this relativity of observations and labels in mind when evaluating these results.


  1. Ditman, K.S., Hayman, M. and Whittlesey, J.R.B. "Nature and Frequency of Claims Following LSD." J. Nervous & Mental Disease,* 1962, 134, 346-352.
  2. Sherwood, J.N., Stolaroff, M.J., and Harman, W.W., "The Psychedelic Experience—A New Concept in Psychotherapy." J. Neuropsychiat., 1962, 3, 370-375. Savage, C., Harman, W., Fadiman, J. and Savage., "A Follow-up Note on the Psychedelic Experience," in Sanford M. Unger (Ed.), Psychedelic Drug Therapy: A New Approach to Personality Change. To be published early in 1964.
  3. A survey of 194 questionnaire returns from the file of Dr. Oscar Janiger was presented by W. M. McGlothlin in "Long-Lasting Effects of LSD on Certain Attitudes in Normals: An Experimental Proposal," a RAND corporation reprint (1962).
  4. Timothy Leary, George H. Litwin and Ralph Metzner. "Reactions to Psilocybin Administered in a Supportive Environment." (To be published in J. Nervous & Mental Disease.)
  5. Grateful acknowledgement is made to the authors of these studies and, in the case of the Ditman Study, to The Williams & Wilkins Company, Baltimore, for permission to reproduce these data.

This article was written by the editors of Psychedelic Review and originally appeared in Psychedelic Review, Issue Number 1, Summer 1963. It has been lovingly transcribed into digital-form by volunteers at The Castalia Foundation. The original text from Psychedelic Review has been edited slightly to fit the format of this web page, but care has been taken not to alter the spirit, intention and meaning of the original article.

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