Snap Out of It: An Electrical Implant to Treat Severe Depression

“Just snap out of it.”  This advice is an all-too-common attempt to help people with depression that, despite being well-intentioned, usually leaves everyone involved frustrated when it doesn’t work. Depression isn’t something you can just ‘snap out of’ – it’s an incredibly complex illness with a myriad of genetic and environmental causes, and so it’s no surprise that treatment takes a variety of forms and affects people in different ways. Current treatments have mostly focused on psychotherapy or medication, and combinations of the two are also common. While the FDA has shown the use of antidepressants and therapy to be more effective than a placebo overall, with symptom reduction in most trials around 50%, there are some patients for whom the standard treatment is inadequate[2]. However, recent research has made remarkable contributions to discovering more effective forms of therapy, medication, and other ways of alleviating depressive episodes. One field that has made significant progress in treating depression is neuroscience, both in understanding brain chemistry and mapping its circuitry.

While neurotransmitters – chemicals that are transmitted between cells in the brain – play an important role in mental health conditions like depression, they are far from the only biological influence. Electrical connections between important regions of the brain can be altered in a way that triggers a depressive episode[3]. Tracking the pathways of emotions in the brain can yield crucial insights into how these connections are related to mental illness. Understanding these changes gives rise to new options for treatment of depression.

One way in which emotions can be traced in the brain is through an MRI scan. Using songs and videos as emotional cues, researchers can utilize MRI scans to view changes throughout the brain and see the pathways that emotions like sadness take[3]. Unfortunately, this technique has a tradeoff: while it can show activity across the entire brain, small-scale brain activity – the precise electrical pathways many researchers are interested in – can get lost in the chaos[3]. That’s where electrodes, devices that carry electrical currents into non-metallic substances, come in[1].

Maryam Shanechi, a researcher at UCSF, has used electrode recordings of brain activity from epilepsy patients to create a detailed map of emotional circuits in the brain. While each individual had their own unique electrical signatures for different moods, everyone shared many pathways in common[3]. One specific region that seemed directly connected to changes in mood was the orbitofrontal cortex. This is the region of the brain directly behind the eyes, and it was strongly associated with emotional states in all patients recorded[3].

Electrical stimulation of the brain has long been an area of interest in treating mental illness, but these findings have shown a new pathway for researchers aiming to develop treatments. Early tests have been promising, with electrodes stimulating the orbitofrontal cortex leading to increased calmness and relaxation among patients, according to their responses when asked how they felt after the test[3]. This result could lead to the development of an implant to literally snap people out of a crisis by using electrical pulses to counteract the electrical signatures of a depressive episode.

How would such an implant work? It would be able to measure electrical signals in the brain and use those patterns to recognize the onset of a depressive episode. The implant would then stimulate the orbitofrontal cortex to reverse the signals of crisis and replace them with signals of calm. By interrupting the circuit of emotional regulation, researchers hope to also be able to interrupt the depressive episode[3].

This implant would not likely be a first line of defense against depression. Treatment via electrical implant would be more invasive than common current methods like medication and therapy. However, for severe depression, this could offer new hope when more traditional methods fail. While such a device is not yet ready and approved for widespread use, an implant to treat depression could be in the near future of mental health care.

References:

  1. Chemistry Dictionary. (2017). Retrieved March 15, 2019, from https://www.chemicool.com/definition/electrodes.html
  2. Khan, A., Faucett, J., Lichtenberg, P., Kirsch, I., & Brown, W. A. (2012). A systematic review of comparative efficacy of treatments and controls for depression. PloS one, 7(7), e41778.
  3. Sanders, L. (2019, February 12). Brain-zapping implants that fight depression are inching closer to reality. Retrieved March 15, 2019, from https://www.sciencenews.org/article/brain-electric-implants-treat-depression-closer-reality?tgt=nr