http://www.erowid.org/chemicals/lsd/lsd_survey_flashbacks.shtml
FLASHBACKS:
Quoted without permission from 'Licit and Illicit Drugs,' written by Edward M. Brecher and the editors of Consumer Reports. ISBN: 0-316-15340-0
A simple explanation of LSD flashbacks, and of their changed character after 1967, is available. According to this theory, almost everybody suffers flashbacks with or without LSD. Any intense emotional experience--the death of a loved one, the moment of discovery that one is in love, the moment of an automobile smashup or of a narrow escape from a smashup--may subsequently and unexpectedly return vividly to consciousness weeks or months later. Since the LSD trip is often an intense emotional experience, it is hardly surprising that it may similarly "flash back."
"Post-traumatic stress disorder has been commonly associated with war veterans, but it also affects victims of disasters and violence... Experts estimate that 1% of the population suffers from the disorder."
---LA Times, Feb 18 1992, p A3, "Journey For Better Life Hell For Some Women."
Can smoking marijuana induce a flashback?
Also are you more likely to suffer flashbacks from having a bad trip?
Apparently yes and yes. The following is reproduced without permission from Lester Grinspoon and James B. Bakalar, "Psychedelic Drugs Reconsidered," Basic Books, Inc. New York, 1979. pp. 159-163. I highly recommend this book, and if you find it please buy me one too.
I typed this in a while ago and didn't type in the references at the time (slap!). If you want them i'll see what i can do. Typos are mine.
... Studies of flashbacks are hard to evaluate because the term has been used so loosely and variably. On the broadest definition, it means the transitory recurrence of emotions and perceptions originally experienced while under the influence of a psychedelic drug. It can last seconds or hours; it can mimic any of the myriad aspects of a trip; and it can be blissful, interesting, annoying, or frightening. Most flashbacks are episodes of visual distortion, time distortion, physical symptoms, loss of ego boundaries, or relived intense emotion lasting a few seconds to a few minutes. Ordinarily they are only slightly disturbing, especially since the drug user usually recognizes them for what they are; they may even be regarded lightheartedly as "free trips." Occasionally they last longer, and in a small minority of cases they turn into repeated frightening images or thoughts. They usually decrease quickly in number and intensity with time, and rarely occur more than a few months after the original trip.
A typical minor and pleasant flashback is the following:
... Frequently afterward there is a momentary "opening" ("flash" would be too spastic a word) when for maybe a couple of seconds an area one is looking at casually, and indeed unthinkingly, suddenly takes on the intense vividness, composition, and significance of things seen while in the psychedelic condition. This "scene" is nearly always a small field of vision -- sometimes a patch of grass, a spray of twigs, even a piece of newspaper in the street or the remains of a meal on a plate.
(Cohen 1970[1965], pp. 114-115)
Here are two more troublesome examples:
For about a week I couldn't walk through the lobby of A-entry at the dorm without getting really scared, because of the goblin I saw there when I was tripping.
(Pope 1971, p. 93)
A man in his late twenties came to the admitting office in a state of panic. Althought he had not taken any drug in approximately 2 moths he was beginning to re-experience some of the illusory phenomena, perceptual distortions, and the feeling of union with the things areound him that had previously occurred only under the influence of LSD. In addition, his wife had told him that he was beginning to "talk crazy," and he had become frightened ... He was concerned lest LSD have some permanent effect on him. He wished reassurance so that he could take it again. His symptoms have subsided but tend to reappear in anxiety-provoking situations.
(Frosch et al. 1965, p. 1237)
Flashbacks are most likely to occur under emotional stress or at a time of altered ego functioning; they are often induced by conditions like fatigue, drunkenness, marihuana intoxication, and even meditative states. Falling asleep is one of those times of consciousness change and diminished ego control; an increase in the hypnagogic imagery common at the edge of sleep often follows psychedelic drug use and can be regarded as a kind of flashback. Dreams too may take on the vividness, intensity, and perceptual peculiarities of drug trips; this spontaneous recurrence of psychedelic experience in sleep (often very pleasant) has been called the high dream (Tart 1972). Marihuana smoking is probably the most common single source of flashbacks. Many people become more sensitive to the psychedelic qualities of marihuana after using more powerful drugs, and some have flashbacks only when smoking marihuana (Weil 1970). In one study frequency of marihuana use was found to be the only factor related to drugs that was correlated with number of psychedelic flashbacks (Stanton et al. 1976).
How common flashbacks are said to be depeds on how they are defined. By the broad definition we have been using, they occur very often; probably a quarter or more of all psychedelic drug users have experienced them. A questionanaire survey of 2,256 soldiers (Stanton and Bardoni 1972), leaving the definition to the respondents, revealed that 23 percent of the men who used LSD had flashbacks. In a 1972 survey of 235 LSD users, Murray P. Naditch and Sheridan Fenwick found that 28 percent had flashbacks. Eleven percent of this group (seven men in all) called them very frightening, 32 percent called them somewhat frightening, 36 percent called them pleasant, and 21 percent called them very pleasant. Sixty-four percent said that their flashbacks did not disrupt their lives in any way; 16 percent (4 percent of the whole LSD-using group) had sought psychiatric help for them (Naditch and Fenwick 1977). In a study of 247 subjects who had taken LSD in psychotherapy, William H. McGlothlin and David O. Arnold found 36 cases of flashbacks, only one of which was seriously disturbing (McGlothlin and Arnold 1971). McGlothlin, defining flashbacks narrowly for clinical purposes as "repeated intrusions of frightening images in spite of volitional efforts to avoid them" (McGlothlin 1974b, p. 291), estimates that 5 percent of habitual psychedelic users have experienced them.
There are few studies on the question of who is most susceptible. In 1974, R. E. Matefy and R. Krall compared psychedelic drug users who had flashbacks with those who did not, and found no significant differences in their biographies or on personality tests. The main causes of flashbacks were stress and anxiety. About 35 percent found them more or less pleasant, and the same proportion thought they could control them. Most accepted them as an inevitable part of their lives as members of the psychedelic fraternity and did not want help from psychiatry (Matefy and Krall 1974). Naditch and Fenwick found that the number of flashbacks, both pleasant and unpleasant, was highly correlated with the number and intensity of bad trips and the use of psychedelic drugs as self-prescribed psychotherapy. Those who enjoyed flashbacks and those who were frightened by them did not differ significantly on tests of ego functioning.
A case seen in an outpatient setting in the late sixties illustrates the kind of set and setting that may create flashback problems. PQ was a thirty-six-year-old single man who entered therapy because of depression and anxiety. He was a heavy drinker who was passive, slovenly, and spent most of his time in bed. Just before taking to alcohol and his bed he had failed in an attempt to parlay a gift from his wealthy father into a fortune on the stock market. Despite a remarkable incapacity for insight, during a year in psychotherapy he managed to give up alcohol and start a promising business. But his anxiety continued, and in order to allay it he had to keep himself very busy wheeling and dealing. Imitating his father, a successful self-made man who had married a woman twenty years younger than himself, PQ dated only women under the age of nineteen. Being attractive to young women was so imporant to him that much of his time was spent in the company of teenagers. During business hours he would wear a conservative three-piece suit and drive a new sedan, but when he was with his young friends he would wear a leather jacket and drive a motorcycle. Anxiety and fears of inadequacy dominated both of these lives. Several months after therapy began, during a weekend in a small resort town, his young friends decided to take LSD, and he felt obliged to dissemble his fears and join them; it was his first and only trip. He felt a panic he had never known before; he thought that he was losing his mind and going "out of control." His friends were so concerned that they took him to a small hospital, where he was given chlorpromazine and after six hours released in their care. The next day he had a flashback that lasted one or two hours and was almost as frightening as the original experience. Flashbacks continued for six months, their frequency, duration, and severity eventually diminishing to the point where it was difficult for him to determine whether they were related to the LSD trip or merely an intensification of his usual anxiety. In fact, the patient described the flashbacks as being like very much enhanced anxiety episodes. Even several years after this experience, when he became very anxious, he was reminded of the trip and these flashbacks. He denied that these experiences had any perceptual or cognitive aspect; both during the LSD trip and later, the only symptom was panic. There is no question that the nature of his trip was influenced by the unfortunate set and setting. It is a matter of speculation what part his underlying chronic anxiety played in the development and form of the flashback phenomena.
Several explanations for flashbacks have been proposed. One is that the drug has lowered the threshold for imagery and fantasy and made them less subject to voluntary control; in another version of this explanation, flashbacks are caused by a heightened attention to certain aspects of immediate sensory experience suggested by drug trips and reinforced by the community of drug users. Something more seems to be needed to account for repeated fearful relivings of sequences from past drug trips, and these have been explained as similar to traumatic neuroses precipitated by fright: disturbing unconscious material has risen to consciousness during the drug trip and can be neither accepted nor repressed. For example, D. F. Saidel and R. Babineau (1976) have reported a case of recurrent flashbacks -- three years of blurring images and auditory distortions, with some anxiety and confusion -- which they regard as a neurosis founded on the patient's problems with his career and his relationship to his mother. (See also Horowitz 1969; Shick and Smith 1970; Heaton 1975.) Another explanation treats the flashback as an example of recall associated with a particular level of arousal. (Fischer 1971). In this conception the memory of an experience is best retrieved when the rate of mental data-processing is the same as it was during the original experience -- in other words, when the state of consciousness in similar. Therefore, psychedelic experiences are likely to be recalled and relived when the ego's sorting and control of sensory information is disturbed by drugs, stress, or the state of half-sleep.
For a critique of flashback studies, see Stanton et al. 1976
