"Hysteria" and Dissociation

Many disruptions of consciousness, such as those seen in the amnesic syndrome, blindsight, anesthesia, and sleep, are associated with clear alterations in the structure and/or function of the nervous system. However, there are other, "functional" alterations in consciousness where nervous-system changes are absent -- or, at least, much more subtle.

"Hysteria"

Historically, the most prominent of these "functional" disorders of consciousness have been subsumed under the label of "hysteria" -- a term that was very popular in psychiatric diagnosis well into the 20th century. The term itself has been abandoned in the "official" nomenclature, represented by the American Psychiatric Association's Diagnostic and Statistical Manual (DSM; since the 2nd edition), along with other terms that carry the flavor of psychoanalysis, such as neurosis and psychosis. However, once shorn of its sexist implications (i.e., that hysteria is a "women's mental illness"), the concept itself is perfectly legitimate. No opprobrium should surround the continued use of the term, so long as it's used responsible.

The term "hysteria" had its origins in the medical literature of ancient Egypt and Greece, and referred to diseases (in women) ostensibly produced by a migrating uterus. For example, a woman who couldn't speak was thought to have her uterus lodged in her throat.

It is mentioned in the Kahun Papyrus, the oldest known medical treatise, dating from18000 BCE.
Also in the Eber Papyrus, dating from1600 BCE.

The "wandering uterus" theory was apparently endorsed by Hippocrates, the "father" of ancient Greek medicine. Although the term "hysteria" does not actually appear in the Hippocratic Corpus, there many mentions of diseases caused by a wandering uterus.
In 1697, Thomas Sydenham, an English physician, abandoned the "uterine" theory, and redefined hysteria to include physical symptoms produced by emotional causes. Still, he thought that hysteria was more frequent in women than in men.
In 1859, Pierre Briquet, a French physician, redefined hysteria again to refer to multiple, chronic physical complaints that had no obvious organic basis. In the 20th century, "Briquet's syndrome" became the basis for the diagnostic category of somatization disorder.

1877, Jean-Martin Charcot, a French neurologist (and director of the Salpetriere Hospital in Paris) redefined hysteria once again, to refer to symptoms mimicking organic illnesses that were produced by emotion and suggestion.

Finally, in 1907, Pierre Janet (Charcot's protege and Sigmund Freud's early rival) argued that the symptoms of hysteria involved a constriction of awareness, such that complex behavioral responses (what Janet called psychological automatisms) were executed outside of conscious awareness and control. In Janet's view, these automatisms were "split off", from the normal stream of consciousness.

Janet (1904, 1907) illustrated his theory with the case of Irene, who is amnesic for her mother's illness and death, but who re-enacts in "somnambulistic" episodes the circumstances of her mother's death.

"Allow me to represent to you this system of psychological facts, which constitutes an idea, by a system of points connected together by some lines, forming a sort of polygon. The point S represents the sight of the face of the dead mother, the point V is the sound of her voice; another point M, is the feeling of the movements made to carry up the body, and so on. This polygon is like the system of thoughts which was developed in the mind and in the brain of our patient Irene. Each point is connected with the others, so one cannot excite the first without giving birth to the second, and the entire system has a tendency to develop itself to the utmost.

"But at the same time in healthy minds these systems pertaining to each idea are connected with an infinitely wider system of which they are only a part, -- the system of our entire consciousness, of our entire individuality. the remembrance of the mother's death, even the affection Irene feels for her mother, with all the memories that are connected with it, forms only a part of the whole consciousness of the young girl with all its memories and other tendencies. Let this large circle, P, near the little polygon represent the whole personality of the girl, the memory of all that happened in her previous life.

"Normally, in good health, the little system must be connected with the large one, and must in great part depend on it. Generally the partial system remains subject to the laws of the total system: it is called up only when the whole consciousness is willing, and within the limits in which this consciousness allows it.

"Now, to picture to ourselves what has taken place during somnambulism, we may adopt a simple provisional resume. Things happen as if an idea, a partial system of thoughts, emancipated itself, became independent and developed itself on its own account. The result is, on one hand, that it develops far too much, and, on the other hand, that consciousness appears no longer to control it" (1907, pp. 41-42).

Sigmund Freud offered an alternative view. In his Studies on Hysteria (1893-1895), co-authored with Josef Breuer, Freud had asserted that "hysterics suffer from reminiscences" -- that the symptoms of hysteria are symbolic representations of traumatic experiences which are not consciously remembered; and that hysteria could be cured by restoring conscious access to the traumatic memory.

In his 1896 paper "On the Etiology of Hysteria", Freud (no longer writing with Breuer) elaborated on this view, based on his doctrine of repression, and involving a particular chain of memories (the graphic illustrating the theory is from Ellenberger, 1970, p. 489).

Freud found that his hysterical patients had invariably been seduced by an adult when they were children. However, this event failed to make an impression on them at the time, and it was passively lost to conscious recollection.
According to Freud, various events of a sexual nature occurring in puberty, themselves often trivial, revived the memory of the earlier seduction. This revival of memory, not the childhood seduction itself, was the trauma instigating the episode of hysteria.
Thereafter, the childhood trauma was actively repressed, leaving the patient at a loss to explain why the hysteria occurred.

Freud's claim that all hysterical patients had been seduced as children made him famous -- and it formed the basis for modern theories of the role of childhood sexual abuse in the dissociative disorders. But in less than a year, Freud was forced to admit, in a letter to his friend and colleague Wilhelm Fliess, that he had been misled, and that his patients' accounts of their childhood seductions had been fantasies on their part (it never occurred to Freud that they had actually been fantasies on his part!). This realization set the stage for Freud's revised (1905) theory of infantile sexuality -- the idea that children harbor erotic attachments to their parents of the opposite sex, and that it is these fantasies, rather than actual sexual trauma, that are repressed.

Dissociative Disorders

Modern psychiatric practice no longer employs the term "hysteria", but does include a category of dissociative disorders including psychogenic (functional) amnesia (named "dissociative amnesia in DSM-5, the most recent version of the Diagnostic and Statistical Manual of Mental Disorders), psychogenic (dissociative) fugue, multiple personality disorder (also known as dissociative identity disorder), and depersonalization/derealization disorder. In these syndromes, the terms "psychogenic", "functional", and "dissociative" are used pretty much interchangeably. In what follows, I adopt the usage in DSM-5.

All the dissociative disorders share in common a disruption in memory and/or identity.

In dissociative amnesia, the patient is amnesic for a particular period of time.

This is not the typical pattern of traumatic retrograde amnesia, which shows a temporal gradient. Rather, there is a complete loss of conscious recollection for some circumscribed period of time -- for example, the four years of high school, with memories of elementary school and college intact and accessible.
The amnesia affects autobiographical, or episodic memory.
There is no evidence of brain damage that would account for the memory disorder, hence the label "functional".
There is a presumed psychological cause of the amnesia, hence the label "psychogenic".

In dissociative fugue, the circumscribed amnesia is accompanied by a loss of identity as well. In other words, the patient has lost semantic as well as episodic self-knowledge.

Identity may simply be lost, or the person may adopt a new identity. In either case, the change in identity is typically accompanied by physical relocation -- hence the name "fugue".
During the period of the lost (or new) identity, the patient loses access to autobiographical memories associated with the previous, usual identity.
The fugue state is temporary. When it has resolved, and the patient has regained his usual identity and autobiographical memories, he is left with an amnesia covering autobiographical memories associated with the period of the fugue.

In dissociative identity disorder, previously known as multiple personality disorder, it appears as if two or more personalities (or identities) inhabit the same person, alternating control over experience, thought, and action.

Each of these identities, or alter egos, is associated with its own fund of autobiographical memory.
When the patient is in one identity, he has access to the autobiographical memories associated with that identity.
When the patient shifts identity, he often loses access to the ABMs associated with the previous identity, but gains access to ABMs associated with the previous identity.
Whereas fugue states occur once, and then are resolved, in DID the alternation among personalities may repeat itself frequently.

In depersonalization and derealization disorder the patient experiences himself or the surrounding environment as somehow changed, even unreal. This is usually a transient condition that resolves itself without active intervention.

Depersonalization may be thought of as a failure to recognize oneself as familiar.
Derealization may be thought of as a failure to recognize the environment as familiar.

More (Much More!) on the Dissociative Disorders

For more thorough coverage of these syndromes, including a history of the diagnosis, see the papers on Dissociation and Dissociative Disorders collected on my scholarly website.

Some psychiatrists claim that the dissociative disorders occur in response to physical or psychological trauma, marking them as a variety of post-traumatic stress disorder (PTSD). However, the traumatic etiology of the dissociative disorders is controversial, and far from proven. For detailed coverage of this issue, see the papers on Trauma and Memory collected on my scholarly website.

And some commentators suggest that people diagnosed with dissociative disorder are just faking it -- enacting a cultural role in order to gain some reward.

Implicit Memory in the Dissociative Disorders

A prominent feature of multiple personality disorder is interpersonality amnesia, such that one personality has no access to memories associated with another personality. This amnesia is often asymmetrical, in that memories associated with one alter ego may be accessible to another, but not the reverse.

Certainly the most famous case of multiple personality disorder was The Three Faces of Eve, described by Thigpen and Cleckley -- first in a professional journal article (1954), and later in a popular-press book (1957) that was turned into a move which won an Oscar for Joanne Woodward. Eve White, the "host" personality, was a somewhat reserved rural Georgia housewife who suffered from "blackouts". During clinical evaluation, a much more vivacious personality emerged, "Eve Black", who apparently had awareness and control of Eve White's actions during those blackout periods. For example, once Eve Black orderd a slinky negligee; it's arrival in the mail surprised Eve White (and disconcerted her husband). A third personality, "Jane", emerged during therapy. "Eve White" had no awareness of "Eve Black" or "Jane". "Eve Black" knew all about "Eve White", but nothing about "Jane". "Jane" knew about everybody.

In another famous case, Jonah (Ludwig et al., 1972), there were four personalities: Jonah, also known as "The Square", was the host personality, an African-American soldier based in the United States, very shy, retiring, and sensitive; he, too, complained of "blackout" periods, where he evidently did things that he couldn't remember later. "Sammy", "The Lawyer", was rather intellectual, and rational. "King Young", "The Lover", was a pleasure-oriented glib talker. "Usoffa Abdulla, the Son of Omega", "The Warrior", was cold, belligerent, and angry. Jonah would go out for a night on the town with his barracks-mates; King Young would try to pick up women; Sammy would try to talk his way out of the inevitable confrontation with their dates; if that failed Usoffa Abdullah would fight his way out of trouble. Jonah didn't know about any of these other personalities, and they had limited knowledge of each other, but they all knew about him.

I.C., a case that my colleagues and I had an opportunity to study, also showed a complex pattern of amnesia. She was a 24-yer-old woman, a world-class performer in her field, who was referred for "disorganized" and self-injurious behavior. As with Eve White, it turned out that there were several other personalities involved: There was "I.C." herself (named for Irene Coriot, another famous case of multiple personality, from the 19th century), married and a mother; "Heather" was still an adolescent; "Joan" was a lesbian; and "Gloria" was a drug abuser. "I.C."'s memories were accessible to everyone else, but "I.C." knew nothing about the others -- though the others knew about each other.

Formal testing of I.C. focused on the "Crovitz-Galton technique", pioneered by Sir Francis Galton (Darwin's half-cousin) and developed further by Herbert Crovitz, an American psychologist, in which a familiar word (e.g., car or dance) is used as a cue for the retrieval of a specific autobiographical memory (e.g., "I remember when my father brought home a new car, a 1955 Plymouth sedan with salmon-pink trim"; "I remember taking Sharon E. to my first school dance in 8th grade"). Because of difficulties gaining access to I.C.'s alter egos, testing focused on I.C., the host personality, herself. We also tested a group of age-matched normal women.

When tested at age 24, I.C. had virtually no memories from the first 14 years of her life, compared to controls
In another session, we constrained her recall to events occurring before age 12. She was able to produce some memories from ages 10-12, but not from earlier ages.
Her earliest recollection of herself was dated to age 12, compared to the more usual dating of about age 4. Her earliest memory of her father was dated age 16.

Based on these findings, we speculated that, perhaps, what we thought was the "host" personality was actually an alter ego that began to emerge around age 12. Unfortunately, we were unable to do further follow up testing with this patient.

The interpersonality amnesia in MPD/DID is usually assessed in terms of explicit memory. However, there is some evidence that implicit memory can "transfer" between personalities. For example, of Jonah, the case described earlier, had been given some laboratory tests of memory, which confirmed his interpersonality amnesia with tests of recall, but showed some interpersonality transfer of memory on tests of savings in relearning (Ludwig et al. 1972).

Because MPD/DID is so rare, most experimental studies have been confined to single cases, like Eve, or Jonah, or I.C. But a study by Eich et al. (1997), compared explicit and implicit memory in a substantial number of such patients. The general design of the study was to present some information to one alter ego (call it P1), and then test memory for that information in the same and a different alter ego (call the latter P2). The results were ambiguous. Eich et al. found no interpersonality priming on a test of stem-completion. But they did find some evidence of transfer on a test of picture-fragment identification. On this test, subjects are presented with a very fragmentary picture of an object, and over trials further details are added until they can correctly identify it.

Preserved implicit memory can be observed in fugue as well as MPD/DID. This was the case with Ansel Bourne, a classic case of fugue studied by none other than William James.

A dramatic example of preserved implicit memory occurred in the case of "Jane Doe", a British woman who was discovered by the police disheveled and wandering the streets (Lyon, 1985). She could not identify herself, and she had no identification and no autobiographical memory. During her clinical evaluation the psychologist tested her fund of semantic and procedural knowledge. He pointed to the telephone on his desk, and asked her what it was. When she responded correctly, he asked her to show her how it was used. She dialed a number and -- before she could replace the receiver on the cradle -- the psychologist took the phone to talk to whoever answered on the other end. That turned out to be the victim's mother. Jane Doe lacked conscious awareness of her memory and identity, but her procedural knowledge -- including how to dial her mother's phone number -- remained intact.

Another recent fugue case, Hannah Upp, was a 33-year-old public-school teacher in New York City who disappeared in 2008 while out jogging. Unlike Ansel Bourne, but like Jane Doe, Hannah did not assume a new identity -- she just lost her usual one. But during the three weeks she was missing, she engaged in some behaviors, like visiting certain sites around the dity, which had been familiar to her before the fugue episode. Most cases of fugue are "one and done": there is a single episode that is not repeated. But Hannah appears to have had a repeat episode about four years later while living in Maryland, under similar circumstances -- at the beginning of the school year. A third episode occurred in 2017, when she was teaching in the Virgin Islands, in the aftermath of Hurrican Irma -- again, just as the new school year was beginning; as of April 2018, she was still missing. (See "Missing Teacher is Found, Alive, Floating in New York Bay" by Al Baker, New York Times, 09/16/2008; and "A Life, Interrupted" by Rebecca Flint Marx and Vytenis Didzulis, New York Times, 02/27/2009. The case, along with other cases of fugue, is discussed in great detail in "The Edge of Identity" by Rachel Aviv, New Yorker, 04/02/2018, from which the information in this paragraph, and the illustration, is taken.)

Obviously, further research is required to clear up these and other ambiguities, but given the present state of the evidence, we can offer the following tentative conclusions:

There is little or no interpersonality transfer of explicit memory between alter egos. This is true almost by definition, as interpersonality amnesia (symmetrical or asymmetrical) is one of the defining features of MPD/DID.
There is some evidence of interpersonality transfer on tests of implicit memory. Transfer is greatest when the possible responses are constrained -- as in Eich's picture-fragment identification test, where there is only one correct response. But there is little transfer when there is considerable freedom of response -- as in the version of the stem-completion test that Eich used, in which there were several possible correct answers.

Conversion Disorders

The conversion disorders involve "pseudoneurological" symptoms affecting sensation and voluntary motor behavior.

In "hysterical", "functional", or "psychogenic" deafness, blindness, or tactile anesthesia, the patient cannot hear, see, or feel stimuli that are normally above threshold.
In "hysterical", "functional", or "psychogenic" paralysis, the patient cannot engage in certain voluntary motor activities.

Sometimes the paralysis affects one or more limbs.
Sometimes it results in aphonia, or an inability to speak.

In all cases, neurological examination reveals no rain insult, injury, or disease that can account for the patient's symptoms.

As with the dissociative disorders affecting memory and identity, the conversion disorders are sometimes referred to as "psychogenic" deafness (or whatever), because they presumably have psychological, rather than organic, causes (if they were caused by some form of peripheral or central nerve damage, they would be seen by neurologists, not psychologists). These symptoms are also functional in nature,

Under the label of "hysteria", the covnersion disorders are among the oldest known mental illnesses, but psychiatry has never known quite what to do with them (Kihlstrom, 1994). The earliest editions of the DSM simply put them under the category of hysteria (where they belonged). But more recently, they have been ensconced in categories like "medical symptoms without known cause". In DSM-5, they are listed under a catch-all category of "Somatic Symptom and Related Disorders".

However, the conversion disorders should be distinguished from other that also involve complaints of bodily dysfunction.

In the psychosomatic disorders, we can see actual anatomical or physiological changes -- for example, in response to stress. But in the conversion disorders, there is no evidence of any organic pathology that would explain the patient's symptoms.
In somatization disorder, sometimes known as Briquet's syndrome, the person has multiple complaints concerning bodily functions other than those directly involving the central nervous system. DSM-IV currently classifies the conversion disorders, along with somatization disorder, as subtypes of somatoform disorder, on the grounds that both syndromes mimic the symptoms of physical illness. But this ignores two facts.

The conversion disorders mimic certain neurological problems, such as deafness or paralysis, while the complaints in somatization disorder are of a sort that would ordinarily be treated by a specialist in internal medicine.
The conversion disorders involve alterations in conscious awareness, while the somatoform disorders do not. Certain clinicians have proposed a new category of somatoform dissociative disorder, but they have not shown that patients with somatization disorder actually experience changes in conscious awareness.

What sorts of changes? In the classical instance, the conversion disorders seem to involve a dissociation between explicit and implicit perception. For example, "hysterically" blind patients are commonly found to be responsive to visual stimuli, even though they are not aware of them. This was noted by Charcot and Janet, as long ago as the19th century -- for example, in Janet's treatise on the Major Symptoms of Hysteria.

Early evidence of visual processing came from a classic study of "hysterical" blindness by Brady & Lind (1961). The patient claimed total blindness, even though medical examination could find no organic pathology that would explain the complaint. As part of their assessment and treatment of the problem, Brady and Lind employed an instrumental conditioning procedure known as the differential reinforcement of low rates (Brady was a psychiatrist who was an early advocate of behavior therapy). The patient was instructed to push a button once within a certain interval, every 18-21 seconds; if he succeeded, a buzzer went off, and he received immediate social approval and accumulated points toward hospital privileges. This is not easy -- not least, because the patient wasn't told precisely what the target interval was; but also because that's a fairly long period of time.

Phase 1 of the study, Trials 1-6, constituted baseline trials, in which the patient pressed the button at will, and got reinforcement, or not, as appropriate. By the end of 6 trials, the patient was correct about 50% of the time.
In Phase 2, Trials 7-16, the subject was presented with a weak visual cue: a change in the ambient illumination of the room during the critical interval. The patient's rate of correct responding immediately went down to about 25%. Over the next 9 trials his response rate recovered to baseline levels, but -- and here's the critical point -- the fact that the patient responded to the change in ambient illumination meant that he was actually responding to visual stimuli.
Phase 3, Trials 17-23, switched to a strong visual cue, in the form of a lightbulb, placed in front of him, that went on during the critical interval. Again, the subject's response rate dropped significantly, but then recovered. By the end of 7 trials, his rate of correct response had actually increased.
In Phase 4, Trials 24-45, the patient was switched to a weaker light bulb, in order to control for the effects of heat radiating from the incandescent filament. The patient maintained his previous level of correct responding until, on Trial 43, he exclaimed "I can see the light!" -- and his response rate promptly fell off. But then it recovered, and increased.
In Phase 5, Trials 46-63, the patient was presented with a more difficult visual discrimination to cue the target interval. On these trials, his response rate continued to increase -- and, throughout, the patient now indicated that he could actually see the discriminative stimuli.

A more recent study by Bryant & McConkey (1989) employed a variant on the Brady & Lind procedure. The subject was presented with a three-choice decision task, in which he had to choose which of three switches to push, in order to get reinforcement. So, just by chance, a person would have a 1/3 chance of making the correct choice. But in this study, a light went on to indicate which switch would be reinforced on any particular trial.

During Trials 1-9, the cue was present. At first, the patient's choice rate was no greater than would be expected by chance; but by the ninth trial, he was well above chance -- showing clearly that, despite his experience of blindness, his behavior was actually being guided by the visual cue.
Just to clinch the point, on Trial 10 the light was turned off, and response rate fell to baseline levels.
On Trials 11-14, the patient was informed that, despite his claims of blindness, his performance showed that he was responding to visual cues. His response returned to the rate observed on Trial 9, and stayed there.
On Trials 15-19, the patient was encouraged to do his best to make the correct choice, and his response rate progressively increased to a perfect 100%.
On Trial 20, the light was turned off, and his rate fell back to baseline.
On Trial 21, the light was turned back on, and the patient's response rate reverted to a perfect 100%.

To summarize, the availability of visual cues increased the patient's response rate above baseline. And when verbal feedback and motivation were added to the visual cues, his performance increased still further. Clearly, the patient's performance was being guided by visual information, despite his lack of conscious vision. In this way, the Bryant & McConkey study, like the earlier Brady & Lind study, showed that explicit perception (indexed by the patient's self report of seeing) was impaired in these patients, while implicit perception (indexed by the patient's actual behavior) was spared.

Just as there is some degree of implicit memory in MPD/DID, so there appears to be some degree of implicit perception in visual conversion disorder.

A Unified View of the Dissociative Disorders

In the final analysis, the dissociative disorders all seem to share the following features:

a disruption in the monitoring and/or controlling functions of consciousness, affecting sensation, perception, memory, or voluntary action;
these symptoms are not attributable to brain insult, injury, or disease;
they are reversible;
there is evidence of intact functioning outside awareness (e.g., implicit perception or memory).

In this view, a taxonomy of dissociative disorders would look like this:

DDs affecting memory and identity, including

functional (psychogenic, dissociative) amnesia,
(psychogenic, dissociative) fugue,
multiple personality disorder (dissociative identity disorder); and
depersonalization and derealization.

DDs affecting sensation and perception, including

"hysterical" (functional, psychogenic) blindness;
"hysterical" (functional, psychogenic) deafness;
"hysterical" (functional, psychogenic) tactile anesthesia; and
comparable "anesthesias" affecting other sensory modalities, such as olfaction and gustation.

DDs affecting voluntary action, including

"hysterical" (functional) aphonia, affecting the ability to speak; and
"hysterical" (functional) paralysis, affecting the ability to engage in voluntary motor activities.