Using the body to calm the mind: An examination of heart rate variability biofeedback as a tool to reduce generalised anxiety disorder symptoms

We all worry from time to time, but for some people who experience an illness called generalised anxiety disorder (GAD), worrying can become uncontrollable, time consuming and distressing. As well as having a negative impact on the way we think and feel, GAD also affects our physical wellbeing. When people experience excessive worry over a long time period, this is often accompanied by changes in the body. One important change is in the time interval between each heartbeat. In a healthy body, the time interval between each heartbeat is not regular. The time gap (measured in milliseconds) between each consecutive heartbeat is called heart rate variability (HRV). High HRV (e.g. high variation in the time between consecutive heartbeats) is associated with a healthy body and mind. Previous research suggests that high HRV is associated with being able to better manage our mood states, for example being able to reduce the intensity of a negative mood state. People with GAD tend to experience low HRV over a prolonged period of time, as there is an association between experiencing very high levels of worry and low HRV. Left untreated, low HRV also puts people at risk of poor heart health later in life.

A recommended treatment for GAD is cognitive behavioural therapy (CBT). This therapy helps people to better understand the relationship between thoughts, feelings and behaviours. Although this treatment is helpful for many people, there is a lot of variation in recovery rates, with only 50% of people recovering from GAD after CBT. This means that while CBT is helpful for lots of people, there are others who do not recover after treatment. It is therefore very important that we examine new approaches to treating GAD.

We know that there is a link between experiencing high levels of worry and experiencing low HRV. One approach that may be successful in reducing key symptoms of GAD such as excessive worry, is to increase people's HRV to see if it reduces worry levels. HRV is linked to breathing patterns, so HRV can be increased by teaching people to beathe at a specific rate. Previous research has shown that increasing people's HRV is associated with lower levels of anxiety. However, this research did not include people who experience very high levels of anxiety and worry (as seen in GAD) and the research did not always have a high-quality design. So, based on the current information we have, it is difficult to draw firm conclusions about the effectiveness of increasing HRV as a treatment for GAD. I propose to examine the relationship between increased HRV and symptoms of GAD and to provide answers as to whether increasing HRV may reduce symptoms of GAD (e.g. reduce worry levels). I will do this by:
1. Examining whether increasing HRV affects the thinking patterns that are known to underpin excessive worry.
2. Examining whether increasing HRV over a number of sessions reduces symptoms of GAD.
3. Examining whether providing a body-based intervention (increasing HRV) in combination with a mind-based intervention (cognitive training to reduce worry) is more effective at reducing GAD symptoms than either intervention by itself.

This research has potential to provide a new type of therapy for GAD. If increasing HRV is as effective at reducing GAD symptoms as other treatments, then this new treatment approach could ensure that service-users have greater choice when thinking about what treatment they would prefer to engage with. If increasing HRV combined with cognitive therapy improves the effectiveness of cognitive training, then there is potential to examine the usefulness of offering both treatments in combination in future research.

Generalised anxiety disorder (GAD) is a common and debilitating illness. A key cognitive symptom of GAD is uncontrollable worry. Physiologically, GAD is typified by low resting heart rate variability (HRV; the time between consecutive heartbeats). Left untreated, GAD is associated with cardiovascular disease. Cognitive behavioural therapy (CBT) is the psychological treatment of choice for GAD, but only 50% of people recover after CBT. It is thus crucial that we develop alternative methods of symptom reduction for use in primary care.

One physiological mechanism showing clinical promise is heart rate variability biofeedback (HRVB). Here, real-time feedback that tracks the relationship between respiration and heart rate is used to increase HRV. HRVB has shown promise as a mechanism for reducing anxiety. Yet, extant research lacks clinical samples and robust methodologies. There is a paucity of knowledge on the causal mechanisms through which HRVB has its effects and the extent to which HRVB reduces symptoms of GAD.

Aims:
1. Establish the relationship between increased HRV and cognitive processes known to underpin pathological worry.
2. Determine the extent to which HRVB multi-session training reduces symptoms of GAD as a standalone intervention, or as a multi-modal intervention targeting both physiological and cognitive symptoms of GAD

Objectives
1. Examine whether increasing HRV in a single session improves performance on executive function tasks and the ability to disengage from worry.
2. Examine the effects of multi-session HRVB on symptoms of GAD as a standalone intervention and in conjunction with a cognitive training intervention.

This research will provide new knowledge of the causal relationship between HRV and cognitive processes impaired in GAD. If HRVB is effective as a standalone intervention or in conjunction with a cognitive intervention, individuals with GAD will benefit from a new treatment approach, offering greater patient choice.