The term conversion originates with Freud (1896/1946), who hypothesized that anxiety, via unconscious mechanisms, was converted into somatic symptoms.

Sexual frustration and conflicts about sexual impulses were long believed to be important forces behind the development of conversion (Mace 1992a, 1992b) and, in many patients, continue to play a role (Merskey and Trimble 1979). However, many contemporary scholars would interpret sexual conflicts or abuse as nonspecific stressors or as antecedent vulnerabilities rather than as the primary etiology for conversion.

Psychodynamic Issues

From a psychodynamic perspective, the etiology of conversion disorder is believed to be the conversion of the anxiety related to unconscious conflicts into somatic symptoms.

The symptom symbolically reflects the conflict and provides a solution to it. A classic example is that of a man whose anxiety about his unconscious rage is converted to a paralysis of the arm. As a consequence, the arm cannot be used to strike another person; therefore, the paralysis represents a symbolic condensation of the unconscious conflict.

Interpersonal Issues

A conversion symptom, because it simulates a disease process, elicits attention, sympathy, and nurturance from others; the patient with the symptom assumes the sick role and benefits from a release from usual societal obligations. In addition, the symptom may prevent the departure of another person or provide gratification of the patient’s dependency needs. It may provoke guilt in others and thus manipulate their behavior and emotions vis-a-vis the patient. An example might be syncopal spells in a woman whose husband is about to embark on a lengthy business trip. Interpersonal issues in conversion phenomenon are so prominent as to beg the question of whether conversion occurs in the absence of social-interpersonal relationships (Taylor 1986).

Conversion as Communication

Some contemporary scholars favor the explanation that conversion is a mechanism of signaling distress or communicating emotions that are forbidden by cultural sanctions or that may bring on retaliation (Hollender 1972; Pu et al. 1986; Roy 1980). For example, conversion symptoms (e.g., swooning) reportedly were frequent in Victorian-era women who were culturally suppressed from the display of either sexual or angry affects. Another example is the presentation of pseudoseizures in a sexually abused wife fearful of reporting her husband to the authorities. Consistent with this communication theory are the data that suggest that conversion (at least in its most nonphysiological simulations) appears to be most common in individuals with lower intelligence or poor education or those who come from an unsophisticated cultural background or a nonindustrial country (Folks et al. 1984; Pu et al. 1986; Weinstein et al. 1969). These factors may impede effective verbal articulation of thoughts and feelings. An alternative explanation is that conversion symptoms are common in better educated and more sophisticated persons but their symptoms more closely resemble genuine disease and/or fall into the category of fashionable diagnoses (Ford 1997b).

Conversion as a Response to Stress or Trauma

Charcot observed that conversion frequently followed a traumatic event (Havens 1966). Conversion has often been observed as a response to a number of varied and systematically studied stressors (e.g., combat, civil disasters) (Bowman and Markand 1999; Ford 1997a). Such events are also frequently associated with dissociative phenomena in a manner that suggests that dissociation and conversion are closely related to each other (Bowman and Markand 1996; Nemiah 1991). Furthermore, conversion symptoms may be a response to the death of another person and thus be part of the mourning process (Daie and Witzum 1991).

Conversion as a Neurological Disorder

Conversion symptoms are frequently found in patients being treated in neurological services and/or patients with cerebral dysfunction (Marsden 1986; Whitlock 1967). This may be because conversion symptoms often mimic neurological disease or because underlying neurophysiological dysfunction may facilitate the development of conversion symptoms (Whitlock 1967). The latter point is of considerable theoretical and practical interest because it partially explains why many patients with conversion symptoms later develop neurological disorders (Slater and Glithero 1965). Although this finding has been used to argue that conversion symptoms represent undetected neurological disease, it seems equally likely that a patient can have a genuine conversion symptom that is facilitated by an underlying neurological dysfunction and that also obscures the diagnosis of neurological disease.

Conversion as a Learned Behavior

According to learning theories, behaviors that are reinforced may become learned and then elicited in response to certain stimuli. Thus, a somatic symptom, irrespective of its original etiology, if reinforced, may be reproduced in response to a particular stimulus. Similarly, a symptom observed in another person may serve as a model for a conversion symptom. A classic example of this phenomenon is the patient who has a seizure disorder or who has witnessed a convulsion. The genuine epileptic fit may elicit powerful effects in the person’s environment. The pseudoseizure may be an attempt to manipulate the environment in a similar manner. It is interesting that a significant proportion of individuals with pseudoseizures do have a true seizure disorder (Bowman 1998; Bowman and Markand 1996; Fenton 1986).

Conversion as a Symptom of Another Psychiatric Disorder

A large proportion of patients with conversion have been found to have underlying depression (Binzer et al. 1998; Marsden 1986; Wyllie et al. 1999). The conversion symptom may be regarded as a socially acceptable mechanism of conveying this psychological distress or may be a depressive equivalent. Effective treatment of the underlying depression may resolve the conversion symptom (Cybulska 1997; Shulman and Silver 1985).

Conversion symptoms also may occasionally occur in schizophrenia (Wyllie et al. 1999; Ziegler et al. 1960). The role of an underlying psychiatric illness is considerable; Mai (1986) stated that a conversion symptom “represents merely the tip of the psychopathological iceberg” (p. 272). Ford and Folks (1985) suggested that conversion should be viewed more as a symptom of another disorder than as a diagnosis.

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Charles V. Ford, M.D.
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