Electrical stimulation of certain parts of the brain cortex has been shown to produce beneficial effects in patients with neurological and neuropsychiatric disorders. A novel modality of electrical brain stimulation is called Transcranial Direct Current Stimulation (tDCS). This technique is getting an increasing attention, as more and more studies show its wide spectrum of uses and low-to-no risk of side effects.
What Is Emotional Instability?
Stressful situations occur every day and not all the persons have the ability to cope with them, which results in emotional instability and in some cases with depression. Chronic imbalance of chemicals in the brain tissue leads to reoccurrence of emotional distress. Although a lot of medications are available for treatment of emotional disorders, there are significant side effects related to their prolonged use (Cascade, Kalali, & Kennedy, 2009). Novel electrical brain stimulation techniques, such as tDCS have been shown beneficial for emotionally unstable persons with frequent mood changes.
Targeting Specific Parts of the Brain
Electrodes used in tDCS are designed to target different parts of the brain, depending on their positioning. For emotional disorders, prefrontal cortex is targeted as it is responsible for modulation of emotions. In other words, emotions are generated in deeper structures of the brain called the limbic system and then processed and modified in prefrontal cortex. Studies have shown that transcranial DCS of the prefrontal cortex improved processing of emotions even in healthy participants (Nitsche et al., 2012).
Different Aspects of tDCS Effects on Emotions
One of the most important psychological approaches to treatment of psychiatric disorders is cognitive-behavioral therapy, which is a type of talk therapy. It is based on discussion of the issues and identification (cognition) of the reasons for bad mood or behavior. It has been shown that tDCS improves cognitive reasoning and cognitive control (Feeser, Prehn, Kazzer, Mungee, & Bajbouj, 2014), which means that it can be used as addition to cognitive-behavioral therapy. Negative emotional reactions, which can appear as a result of social rejection and non-acceptance, can also be treated with tDCS with high success rates (Pena-Gomez, Vidal-Pineiro, Clemente, Pascual-Leone, & Bartres-Faz, 2011).
One study investigated whether tDCS can affect the emotional response to visually experienced scenes of violence. They have found that tDCS significantly decreased the recall of the unpleasant situations, while it promoted the recall of pleasant and neutral events (Penolazzi et al., 2010). This method also enhanced the experience of positive emotions in experimental settings of another study (Vanderhasselt et al., 2013).
In conclusion, there are scientific evidences that tDCS can help people with emotional distress to speed up the recovery and go through the stressful period more easily. As an addition to cognitive-behavioral therapy, it can be used in psychiatric patients to prevent mood changes and relieve their symptoms.
References
Cascade, E., Kalali, A. H., & Kennedy, S. H. (2009). Real-World Data on SSRI Antidepressant Side Effects. Psychiatry (Edgmont), 6(2), 16-18.
Feeser, M., Prehn, K., Kazzer, P., Mungee, A., & Bajbouj, M. (2014). Transcranial direct current stimulation enhances cognitive control during emotion regulation. Brain Stimul, 7(1), 105-112. doi: 10.1016/j.brs.2013.08.006
Nitsche, M. A., Koschack, J., Pohlers, H., Hullemann, S., Paulus, W., & Happe, S. (2012). Effects of frontal transcranial direct current stimulation on emotional state and processing in healthy humans. Front Psychiatry, 3, 58. doi: 10.3389/fpsyt.2012.00058
Pena-Gomez, C., Vidal-Pineiro, D., Clemente, I. C., Pascual-Leone, A., & Bartres-Faz, D. (2011). Down-regulation of negative emotional processing by transcranial direct current stimulation: effects of personality characteristics. PLoS One, 6(7), e22812. doi: 10.1371/journal.pone.0022812
Penolazzi, B., Di Domenico, A., Marzoli, D., Mammarella, N., Fairfield, B., Franciotti, R., . . . Tommasi, L. (2010). Effects of Transcranial Direct Current Stimulation on episodic memory related to emotional visual stimuli. PLoS One, 5(5), e10623. doi: 10.1371/journal.pone.0010623
Vanderhasselt, M. A., De Raedt, R., Brunoni, A. R., Campanha, C., Baeken, C., Remue, J., & Boggio, P. S. (2013). tDCS over the left prefrontal cortex enhances cognitive control for positive affective stimuli. PLoS One, 8(5), e62219. doi: 10.1371/journal.pone.0062219