When it comes to mental health and the accompanying conditions that come with it, experts believe that there may be a misreading of internal bodily signals. In fact, a new study from the University of Cambridge in the UK suggests how signals in one specific area of the brain become disrupted for those with the condition. Their finding are applicable to a wide range of mental health problems, and somehow, they are linked together in a new way. Moreover, they say that current treatments do not affect this area in the brain. They have stated that medications that target these problems are actually quite helpful.
Signals of Interoception
Our body is continually sending signals, or cues. These inform our brains when we are in pain, when we are starving or are thirsty, when we need to sleep, and so many other bodily functions. Experts now have a word for this. Our perception of the internal signals is also known as interoception.
Dr. Camilla Nord, lead author of a new study from the University of Cambridge in the U.K., talked about this and said, “Interoception is something we are all doing constantly, although we might not be aware of it. For example, most of us are able to interpret the signals of low blood sugar, such as tiredness or irritability, and know to eat something.”
However, in the case of certain mental health conditions, interoception can occur in a variety of different ways. For instance, those who suffer from anorexia may feel full when, in reality, they are not. Those who suffer from a panic attack may feel they the need for more air even when they already have enough to breathe properly.
The study that the researchers made has pointed out and identified an area of the brain that functions differently in those who suffer from mental health conditions. The discovery made actually sees a previously unknown connection between bipolar disorder, anxiety, major depression, anorexia, and schizophrenia.
The researchers had come up with several conclusions that could also represent an opportunity for new treatments to be made. This is seen as a good sign because current antidepressant medications and psychological therapies do not address this region of the cerebellum. In fact, the details of the study appear in The American Journal of Psychiatry.
The Common Thread Seen in Brain Scans
It has become apparent to the researchers that interoceptive disruption may, in fact, be a driver of certain conditions, such as anorexia. This was what Dr. Walter Kaye told Medical News Today. He is the founder and executive director of the University of California San Diego Eating Disorder Research and Treatment Program and also the lead author of a previous study that investigates interoceptive miscues.
Dr. Kaye explained, “We are very interested in this issue in the eating disorders field, as it likely is involved in body image distortion and lack of response to hunger but no proven treatments so far.” And as the study authors see and note, many studies reported that brain activity during interoception is somewhat converted and changed in several mental health conditions. However, is yet to be fully explained and discovered whether these interoceptive differences are all underpinned by the same brain region and across every type of mental condition.
The authors needed to investigate the possible existence of a common brain malfunction. To make this possible, they performed a new meta-analysis of existing neuroimaging data. The final sample came from 33 separate experiments and the researchers compared functional MRI (fMRI) scans from 626 people who suffer from mental health conditions with 610 control participants. Part of the sample were those with unipolar and bipolar depression, anorexia in remission, anxiety, and schizophrenia.
According to Dr. Nord, “We wanted to find out whether there is something similar happening in the brain in people with different mental disorders, irrespective of their diagnosis.”
As for Dr. Kaye, she explained, “It may be that most or all behavioral disorders involve the circuits in the brain that modulate neural processes for appropriate decision making in response to internal and external stimuli. Disorders may differentially impact parts of this system, resulting in a range of symptoms.”
Disrupted Activity Found in One Specific Area
The fMRI scans performed showed very interesting results that revealed disrupted activity in the cerebral cortex’s dorsal mid-insula cluster as those tested with mental health conditions were processing interoceptive signals. These signals were akin to hunger, pain, and other internal cues, such as those associated with tickling and itching sensations, heat, and thirst.
Further analysis was made and it was revealed that the region of the brain implicated in affective processing (region in charge of dealing with emotional feelings, mood, and attitudes) was distinct from the cluster in charge of interoceptive signals. While there was activity from affective processing in the nearby region, the researchers didn’t see an overlap. Thus, the signal from the observed activity was clearly associated with interoceptive processing.
Still, this analysis wasn’t enough for them to come to a conclusion. Hence, the researchers performed a third analysis. This was designed to explore the degree to which existing psychological treatments or antidepressants for affective disorders might have some impact or effect on the brain cluster observed. Again, they didn’t come an across an overlap still. This could only mean that the dorsal mid-insula cluster may be an unexplored, unique target ideal for pharmacological intervention.
Dr. Nord plans to make further investigations on the use of new mental health treatments, such as brain stimulation, as a way of promoting normal functioning in the cluster. From the studies done, she came to a conclusion and shared, “It’s surprising that in spite of the diversity of psychological symptoms, there appears to be a common factor in how physical signals are processed differently by the brain in mental health disorders. It shows how intertwined physical and mental health are, but also the limitations of our diagnostic system — some important factors in mental health might be ‘transdiagnostic,’ that is, found across many diagnoses.”