What is PTSD?
PTSD is a mental condition of anxiety that is triggered by a terrifying event, either by experiencing it or by witnessing it. Traumatic events that trigger PTSD may include accidents, natural-human caused disasters, personal assaults etc. Several effective treatments, such as antidepressants as serotonin-specific reuptake inhibitors (SSRIs) and Cognitive Behavioural Therapy have been identified as treatments for PTSD, however even with these a number of patients continue to experience symptoms. This means that treatment for chronic PTSD is still inadequate. The neuroscience has revealed that patients suffering from PTSD have altered functioning within several brain regions. Researchers say that a non-invasive electrical brain stimulation is a very effective treatment for Post Traumatic Stress Disorder (PTSD) by seemingly correcting the dysfunctional brain parts. It is believed that this, in turn, results in relief of PTSD symptoms.
The non-invasive transcranial Direct Current Stimulation tDCS has been experimented to treat many mental conditions like schizophrenia, depression, obsessive compulsive disorder, stroke and many more. When we talk about PTSD, one of the main problems with this disorder is the inability to escape fearful thoughts. Such as flashbacks of a friend being killed in a car accident. Such flashbacks can aggravate PTSD Symptoms which may also include anger, insomnia, nightmares and irritability.
tDCS decreases Emotional Arousal and Fear in PTSD patients:
Several studies were carried out that involved the use of tDCS to treat PTSD and their results were carefully observed.
During tDCS, a low-intensity current enters through one electrode and leaves through the other. The neurons, under the electrode where the current enters the body, become more likely to send signals, and under the electrode area where the current exits the skin, neurons are less likely to send signals.
A study involved 28 people suffering from PTSD. The researchers took help of an event marked by conditioned reflex, in which the patients predicted an unpleasant event after seeing a neutral stimulus. Coloured lights were marked as neutral stimulus and the unpleasant event attached to it was a harmless but highly annoying current to the fingers. The researchers put the electrode, through which current enters the skin, over a region which plays an important role in extinction learning and memory called ventromedial prefrontal cortex. The purpose was to make sure that those neurons fire off more likely to see if this improved extinction learning or the ability to predict an annoying event. At first, the 28 patients were made to see a colored light in a room, and, simultaneously, were given electric shock. Later, the patients were shown the coloured light without applying the electric shock. The later event is what we call extinction learning; the process where one learns that certain situations no longer anticipate an annoying event.
Fourteen patients received 10 minutes of tDCS just when they were experiencing extinction learning. The other 14 were given tDCS just after they underwent extinction learning, a time period known as extinction consolidation, when the information is being fed into the memory. After 24 hours, all of these patients were tested if they remembered the electric shock or not.
The results showed that the 14 veterans who received stimulation during the time of extinction consolidation showed slightly less perspiration on their hands (which was a sign of less fear/emotional arousal) than those who experienced the tDCS during extinction learning. An increase in hand sweat showed how well the patients had learnt and remembered that seeing colored light will result into a very unpleasant shock to their fingers.
It could be taken as giving the brain a little boost when people learnt that the colored lights no longer predict an electric shock and store that learning into memory, so people can better remember that they don’t need to fear the lights any longer.
For tDCS to be more effective, it is very important to control what the brain is doing during tDCS. That is why people were stimulated when they were doing an experimental task of extinction learning or consolidation of learning.
Brain stimulation technique shows promise in reducing fear in Veterans with PTSD. (2017, december
9). Retrieved from US Department Of Veteran Affairs: https://www.research.va.gov/currents/1117-Brain-stimulation-technique-shows-promise-in-reducing-fear-in-PTSD.cfm
Current Status of Transcranial Direct Current Stimulation in Posttraumatic Stress and Other Anxiety Disorders. (2016, april 2). Retrieved from NEURAL ENGINEERING GROUP: https://www.neuralengr.org/uncategorized/new-paper-prospects-of-tdcs-for-ptsd/
ain Stimulation for Post-Traumatic Stress Disorder . (n.d.). Retrieved from Grantome: http://grantome.com/grant/NIH/R21-MH102539-02
Post-traumatic Stress Disorder Treatment Using Transcranial Direct Current Stimulation (tDCS) Enhancement of Trauma-focused Therapy. (n.d.). Retrieved from Smart Patients : https://www.smartpatients.com/trials/NCT02900053
tDCS improves behavioral and neurophysiological symptoms in pilot group with post-traumatic stress disorder (PTSD) and with poor working memory. (2014, feb 28). Retrieved from Taylor and Francis Group: https://www.tandfonline.com/doi/abs/10.1080/13554794.2014.890727