Processes in brain metabolism that can explain why anorexic patients drastically reduce food intake, and are often incapable of changing their behaviour, according to a study by scientists at Heidelberg University Hospital.
Writing about their work in the prestigious American Journal of Psychiatry, the researchers revealed that they examined a total of 30 young women with and without anorexia by means of functional magnetic resonance imaging (MRI).
The MRI device recorded the level of blood flow in various areas of the brain.
It may be useful to note here that greater blood flow indicates higher metabolism, and thus greater activity.
The participants underwent a test that measured their capacity for flexible behaviour modification of recently learned behaviour.
As part of this test, they were shown a rapid sequence of various geometric shapes, and asked to match them. After one test run, the matching principle was changed.
"In this study, we confirmed that anorexic patients cling to familiar behavioral responses more frequently than healthy subjects, thus suppressing alternative behavior," said Dr. Hans-Christoph Friederich, head of the working group for eating disorders.
Analysing the MRI images, the researchers observed that in patients with anorexia compared with healthy subjects, a certain network pathway between the cortex and the diencephalon is less activated.
The researchers say that this network pathway plays a decisive role in initiating and controlling actions under rapidly changing environmental demands.
They say that the study's findings contribute decisively to a better understanding of anorexia.
In particular, say that researchers, the results make it clear that neurobiological factors are involved and sustain the clinical symptoms.
Given that psychological and neurobiological factors can influence each other, the researchers say that this may lead to new therapy approaches for anorexia.
"We have developed a treatment program for anorexia patients that specifically targets the flexible modification of behavioural responses," says Dr. Friederich.
In this way, the researchers hope to improve the success of psychotherapeutic treatment.
They believe that the MRI examination of the brain could contribute to measure the success of treatment.