Most people are likely to know botulinum toxin Bacterial Toxin (BTX) – better known as Botox – as a treatment for wrinkles. But botulinum toxin can do more: If injected into the forehead, for example, it can relieve depression.
It also dampens negative emotions in people with borderline personality disorder, who suffer from severe mood swings.
Prof. Dr. Tilmann Krueger, Senior Clinical Physician and Research Group Leader in the Clinic for Psychiatry, Social Psychiatry and Psychotherapy at the Medical School Hannover (MHH), demonstrated this years ago – along with fellow Privatdozent (PD) Dr. Marc Axel Wollmer of the Asklepios Campus in Hamburg Semmelweis University.
Now psychiatrists have discovered where and how BTX affects the negative program in the brain. With the help of magnetic resonance imaging (MRI), they visualized the neurological effects in borderline patients.
The result: Botulinum toxin affects the so-called amygdala, or amygdala nucleus, in the temporal lobe of the brain, where fears arise and are processed.
The work was recently published in the journal Scientific Reports.
Muscular and psychological reactions
Negative moods on the face are expressed in the so-called glabellar area, which is the area below the middle forehead. When we are angry or tense, two different types of muscles contract and cause frown lines or lines of anxiety to appear above the root of the nose.
When botulinum toxin is injected into the polar region, it paralyzes these muscles between the eyebrows. Since facial expressions and psychological state are closely related, this also reduces the intensity of emotions.
“A sagging forehead conveys a more positive feeling, so to speak,” Professor Krueger explains.
In science, these observations are discussed as the theory of facial reactions. In a previous meta-analysis, Professor Krueger and his team have already shown that injecting BTX into the glaballar area has a positive effect on mood and mood awakening.
Symptoms of depression improve significantly as a result. “The treatment has several advantages at once: because the paralysis effect lasts for three months or more, an injection should also be given only in these periods. Prof. Krueger explains that non-recurrent injections are also less expensive than some other treatment options and are well tolerated. high and well accepted among patients.
Botulinum toxin limits the persistent emotional fire in the tonsil nucleus
This works with depression as well as for borderline personality disorder. About 3% of Germans suffer from this disorder, and more than 62% of those affected are women. By interrupting the feedback loop between the forehead muscles and the brain, botulinum toxin also alters emotional reactions.
The researchers were able to prove this in the brains of patients treated with botulinum toxin injections in the polar region. After just four weeks, patients had significantly reduced symptoms, which were also shown on MRI images.
“We were able to see that botulinum toxin limits the persistent emotional fires in the tonsil nuclei, which accompanies the high-grade internal stress of affected people,” says the psychiatrist. The acupuncture-treated comparison group also showed improved clinical symptoms, but not neurological effects on the MRI scan. However, the feedback between the muscles and the brain does not work only in the polar region.
This is the result of a database study involving Professor Krueger and his colleague Professor Walmer which has already been published in the journal Scientific Reports at the end of 2021.
In collaboration with the University of California San Diego, they found that botulinum toxin can also relieve anxiety disorders when injected into the muscles of the head, muscles of the upper and lower extremities, and muscles of the neck.
To date, however, BTX treatment for mental illness has not been included in the services provided by health insurance companies. The psychiatrist hopes this will change when the modus operandi is better researched.
Botulinum toxin, colloquially known as Botox, is the most powerful neurotoxin known. It is produced by Clostridium botulinum bacteria in the absence of air and causes what is called food poisoning. Symptoms of poisoning are usually caused by eating poorly preserved food containing bacterial toxins. This prevents the transmission of excitation from neurons to other cells, especially at the junctions of muscles and blood.
About this borderline personality disorder and emotion research news
author: Stefan Zorn
Contact: Stefan Zorn – MHH
picture: Photo credited to Karin Kaiser / MHH
original search: open access.
“Neural effects of glabellar botulinum toxin injection using an enhanced inhibition task in borderline personality disorder” by Tillmann HC Kruger et al. Scientific Reports
Neurological effects of glabellar botulinum toxin injection using an enhanced inhibition task in borderline personality disorder.
Previous studies have indicated that botulinum toxin (BTX) injections may lead to sustained relief of depression. This can be achieved by disrupting the facial feedback loop, which is likely to mitigate the experience of negative emotions.
Accordingly, glabellar BTX injections can dampen amygdala activity in response to emotional stimuli. A typical case containing an increase in negative emotion and impulsivity accompanied by an elevated amygdala reactivity to emotional stimuli is borderline personality disorder (BPD).
In order to better understand how glabellar BTX affects the processing of emotional and impulsive stimuli, we performed a functional magnetic resonance imaging (fMRI) study.
Our hypotheses were that (1) glabellar BTX leads to increased activation in frontal lobe regions during performance of inhibition and (2) BTX decreases amygdala activity during processing of emotional stimuli in general. Using the emotional go-/no-go paradigm during functional magnetic resonance imaging, an emotion and impulsivity processing intervention was evaluated in a sample of n = 45 women with BPD.
Subjects were randomly assigned to BTX treatment or serial acupuncture (ACU) to the head. After 4 weeks, both treatments resulted in a reduction in BPD symptoms.
However, BTX treatment in particular was associated with improved inhibition performance and increased activity in the motor cortex. In addition, processing negative emotional faces was associated with a decrease in right amygdala activity.
This study provides the first evidence that glabellar BTX injections may modify the central neurobiological and behavioral aspects of borderline personality disorder. As the control treatment produced similar clinical effects, these neurobiological findings may be specific to BTX and not generally related to symptom improvement.