Conversion disorder was given its name by Breuer and Freud, who believed its symptoms originated from the conversion of psychological stress into somatic symptoms. More than a hundred years later, this is still the predominant perspective. However, over the past few years, neurobiological research has been conducted to further explore the disorder. Some researchers argue that recent neurobiological findings contradict the predominant perspective, whereas others believe these findings highlight the mechanism by which psychological stress can result in physical symptoms.
Author: Lineke Tak
In DSM 5, the diagnostic criteria for conversion disorder (also called functional neurological symptom disorder) have been amended. In DSM 5, the psychosocial stressor associated with the physical symptoms no longer needs to be identified. Furthermore, a new criterion was added: neurological symptoms that support the diagnosis of conversion disorder need to be identified.
In the research paper described here (Ludwig e.a., 2018), the authors start off by explaining that stressful life events and maltreatment have traditionally been considered crucial in the development of conversion (functional neurological symptom) disorder. They then use systematic review and meta-analysis to study the association between the disorder and stressful life events and maltreatment (sexual abuse, physical abuse or emotional neglect) in childhood or adulthood.
34 case-control studies were found, with a total of 1405 conversion disorder patients. The patients suffered from paralysis, motor deficits and unresponsiveness. There were 2227 controls; both healthy individuals and patients with a neurological or psychiatric disorder.
Childhood and adulthood stressors, especially emotional neglect, were more common in conversion patients compared with controls (see table 1). The studies included were of moderate to low quality. Heterogeneity between studies was high. The association with pre-onset stressful life events was stronger in studies with a better methodology. Furthermore, the association was stronger in the case of healthy controls compared to patients with a neurological or psychiatric disorder.
Table 1: Percentage conversion patients versus controls reporting stressful life events in childhood
| Childhood life event | Conversion disorder | Controls |
| Emotional neglect | 49% | 20% |
| Sexual abuse | 24% | 10% |
| Physical abuse | 30% | 12% |
It is difficult to say if these numbers reflect reality. The authors identified several unknown factors; for instance, they were unsure of the participants’ willingness to reveal sensitive information, the accuracy of participants’ memories (recall bias) and the relevance of the reported stressful life events in the development of a conversion disorder. Furthermore, it was unclear whether ‘minor’ stressors, which are not measured with the questionnaires used but could bear some relevance, were identified.
In conclusion, stressful life events and maltreatment were substantially more common in patients with conversion disorder than in controls. Childhood emotional neglect was more common than (the traditionally emphasised) sexual abuse. A varying but in some studies substantial proportion of conversion disorder patients reported no stressful life events. The results of this meta-analysis therefore support the recent changes in DSM 5, removing identifiable psychological stressors as a diagnostic criterion.
The authors emphasise two sides to their findings that are important in daily clinical practice. On the one hand, stressful life events are worth considering and examining, as they are more prevalent in conversion disorder patients and can be an important focus in treatment. On the other hand, if no stressors come to the surface, there is no need to assume the patient is consciously or subconsciously withholding them. In the authors’ experience, patients without reported stressful life events also improve during therapy. A continuous search for a ‘stressful life event’ as the cause of the conversion disorder can be just as harmful as ignoring it.
Source
Ludwig L, Pasman JA, Nicholson T, Aybek S, David AS, Tuck S, Kanaan RA, Roelofs K, Carson A, Stone J. Stressful life events and maltreatment in conversion (functional neurological) disorder: systematic review and meta-analysis of case-control studies. Lancet Psychiatry. 2018;5(4):307-320.