I have overlooked this brain scan study of 6.patients from Switzerland with some germans co authors from 2020. Until 2013-15 there was two small research units doing research into depersonalization. One in New York and one at King´s College in London. These were very poorly staffed with around 4-5.people working permanently there and some ph.d students and external researchers from other places coming there for a specific study. The studies were all very small in size likely due to the lack of funding as depersonalization is so mis and under-diagnosed until recently. So, almost every publication coming out had relation to these to units for nearly two decades. Now, they are closed. The positive side of it is that there are coming studies from other countries. One angular gyrus trial in France, one scan in Japan, two structural MRI/DTI scans in Germany and now this small study from Switzerland. So, there is increased awareness about the disorder in other countries and that is positive.
Brain scans of depersonalization is closely related to rTMS as a potential treatment. If a location, network can be found to be over or underachieve it could in theory be stimulated with rTMS and the state would normalize. Both former research units tried to find such locations and do some very small trials at them with the rTMS technology available back then. That excluded many locations as they were to deep for stimulation with conventional rTMS back then.
The study from Switzerland brings challenges to locations also the models previously used. The former model thought of a model with a overactive prefrontal cortex that suppressed the limbic system (area for emotions) This overactivity should make a state of numbing/having no emotions, detachment, unreality. With rTMS is was thought the inhibition of such a overactive area would take depersonalization away.
The German studies put this model in to question. They also said the the size of the studies previously done was very small. Below a minimum of 20.patients. They agreed though that rTMS would likely be the intervention.
This study was done with a scanner called ALS-MRI that is similar to a fMRI but uses the iron in the blood of the brain as a tracer for brain metabolism.
They found a significant under activity in the left orbitofrontal cortex that is involved in sensory integration in pre-psychotics with DP/DR symptoms. They think that it this under-activity or failure of this area to make a integration of sensory input that makes some part of the disorder. The emotional numbing do not come from emotional supression but a failure to integrate them.
They also found a overactivity in the very dopamine rich area in the brain called the left Caudate nucleus that is a location deep in the brain that is also very affected in states like obsessive compulsive disorder. So, an element of having OCD like symptoms in depersonalization is likely related to this.
This can likely be changes with the type of rTMS equipment used in research.
The study is very small as all previously studies done but it puts a major challenge to the models previously used in depersonalization. It can be read here. It is very small but points towards the need for more newer and larger brain scans done.
There was a review of the brain studies done to date in depersonalization last year and they pointed towards the conflicts about locations, networks that have only become worse with this study. They recommended to do a study were a combination of advanced rTMS with rMRI was used. So, a location coming up as over or underachieve was stimulated to some sessions in 10-15.patients to see if there was any reductions in symptoms and then scan them again and see if some of the brain had normalized or changed.An area could also be ruled out as having any relevance. It could also be that some locations works in 50% and not in the rest and people with depersonalization in reality have some differences in their emotional regulation done by the brain-
There is a need for a research unit that can work with this continuously with many patients. The germans wrote they had difficulties finding sufficient number of patients, The French angular gyrus trail have been under way for 6.years likely also due to the lack of patients in a Paris area. The Swiss study wrote that they difficulties finding people with "pure" depersonalization (many have is secondary to another disorder and can not be used). Many with "pure" depersonalization they contacted in Switzerland declined to take one hour out for a brain sca. So, a research unit can likely only be in the London area or New York/Boston as many likely there have been seen by the former research units and many local psychiatrists are aware of the disorder.A research unit shall be in an area with 300-500.people with "pure depersonalization" who will be a part of research For legal reason a research unit can only take nationals of the authorities that have approved the research.