Listen to your heart: Linking heart and brain for depression

Abstract

People with depression often experience higher heart rates and lower heart rate variability. Furthermore, they have a five-fold higher chance on heart disease. Thus, there is an interplay between the brain and the heart, that is dysregulated in people with depression. New research suggest that the brain-heart connection may be used to improve and personalize depression treatments. This is needed since even with a broad availability of treatments, 40-50% of depressive patients do not respond. One form of treatment is brain stimulation, aimed at different brain regions that are involved in depression. Studies have shown that non-invasive stimulation of these targets led to heart rate decelerations. This can be used to determine the exact location of these brain areas. To clarify: If you compare different heads you cannot tell the exact location of certain brain areas. Every head is different, however the commonly used methods to find the correct stimulation target are based on a group mean. This is why more recently the brain areas’ underlying function is studied in order to locate the structures. In this thesis it is explored whether the connection to the heart may be informative about whether the correct brain area is being stimulated. This was the case: In 3 different studies it was found that stimulation, on an in depression implicated brain area, led to heart rate decelerations, while stimulation on other areas did not or showed this less. Thus, the areas that are implicated in depression may be located using heart rate, but it has to be further examined whether this leads to higher treatment efficacy.