Estimation of the Prevalence of Body Integrity Dysphoria (BID) in German-Speaking Countries Based on the Use of an Internet-Forum by Those Affected
Authors:   Practice for Psychotherapy and Neuropsychology, Am Krautacker 25, D-23570 Travemünde, Germany., Kasten Erich 
Published: May 2024

Body Integrity Dysphoria (BID, BIID) is a disease of unknown cause, in which those affected have the intense feeling that a part of the body does not belong to them. BID-sufferers can feel and move the corresponding limb, but it is not part of their mental body image. Estimating the prevalence of BID is very difficult due to the fact that most sufferers do not confide their suffering to anyone. However, the situation has changed since the widespread use of various Internet platforms. The basis is that in the three German-speaking countries (Germany, Austria, Switzerland) most adults have access to the Internet and, sooner or later, are looking for information about the strange feeling that parts of the body don’t feel like they belong. It can therefore be assumed that many of those affected will at some point register in such a forum in order to exchange ideas with others. The quantities are estimates from: (a) Number of BID affected people in the German speaking BID-DACH forum, (b) Number of BID affected people registered in BID forums in the German speaking areas, (c) Number of those affected by BID who do not register but inform via social media, (d) Estimation of the total number of people affected by BID from (a), (b) and (c). According to this model, the prevalence is in the range of 1 in 5,500 (0.018%) to 1 in 22,000 (0.0045%), mean value is in the range of 1 in 11,000 (0.01%). According to the data from Fischer et al (2015) and Garbos et al (2022), the severity of BID follows a normal distribution. This means that 16% have a very mild form, they feel relatively little pressure and they are often probably not even aware that they are suffering from BID at all. The middle 68% from a statistical perspective have a moderate form of BID. Most achieve sufficient catharis with occasional pretending and often do not seriously pursue real disability. Serious candidates for an amputation or other forms of disability are those with an above-average level; they include the top 16% of the distribution. Of these 1,500, around half suffer from the need for amputation, the other half have a desire for paraplegia or other forms of disability. Here it is to be expected that they will want an operation in the long term. This value can be justified rationally, because every realization of the need for disabilities is associated with massive restrictions in everyday life. Those affected are well aware of these limitations and even in the group of severe cases, most people delay it for decades before giving in to the need and having an operation (or other options) carried out. If we assume that the 750 people ready for amputation are spread across the age group 20-70 years, after processing the backlog of old cases, then a maximum of 15 new candidates for amputation per year would be expected. This model refers to the German-speaking area because the forum is conducted in German. However, it seems entirely permissible that a similar prevalence value can also be assumed for several other countries.