The third in a trio of research papers was published this week that explore the link between mental and physical health in people with Tourette Syndrome and Chronic Tic Disorders. NIHR Clinical Fellow Dr Victoria Pile has been investigating the part memories, attention and other processes play in anxiety or depression in people with Tourette’s. Her Fellowship is shared between the BRCs at Guy’s and St Thomas’ and South London and Maudesley. We caught up with Dr Pile to talk about her research, and why she hopes this might be used to improve treatment for people that have both conditions.
Your research explores how Tourette’s and conditions like depression and anxiety interact. What made you want to research this area?
As tics are more obvious to people than depression or anxiety, most research on Tourette syndrome and Chronic Tic Disorders (TS/CTD) has focused on the role of the brain in these movements. However, we know that depression and anxiety are really common in TS/CTD and really impact on the young person and their family. Lots of the families that we see say that anxiety and depression is more of a problem for them than the tics. Yet there is very little guidance on how best to manage anxiety and depression in young people with TS/CTD. I am really passionate about trying to better understand anxiety and low mood in the context of TS/CTD and so be able to improve available interventions.
Do we know why people with Tourette’s are more prone to conditions like depression and anxiety?
The simple answer is no. There are lots of reasons why young people with TS/CTD might be more vulnerable to depression and anxiety. These include biological, psychological and environmental factors. What we do know from the general population is that there are certain thinking styles that make people more likely to develop depression and anxiety. In these projects, we investigated three different ways of processing information in TS/CTD.
You looked at memory and how that interplays with depression. What features of memory were you exploring, and what did you find?
The way in which we remember events in our lives seems very important to understand why some people might be more likely to develop depression.
For example, in response to the word “grass”, you could give me different types of memory. You might give a memory that is specific. These are memories that identify unique events that occurred at a particular time and place. For instance, ‘we had a picnic on the grass last Saturday’. Alternatively, you might give a general memory, such as ‘I cut the lawn every two weeks’ or ‘I developed hay fever last summer’. Having more general memories is linked to depression.
In this project, we found that young people with TS/CTD have more general memories, compared to other young people their age. We also found that having general memories for positive events was associated with symptoms of depression. This helps us to understand why depression is more common in TS/CTD, and to develop interventions that could prevent depression.
Interoceptive accuracy is something you measured in Tourette’s – what exactly is it, and what did you find out about it?
Interoception refers to an ability to be aware your own internal signals. Interoceptive accuracy (IA) is the measurement of this using a task that asks you to count the number of heart beats you have in a period of time. The closer you are to the correct number, the better your interoceptive accuracy.
IA has been linked to TS/CTD as often people with TS/CTD report experiencing a sensation in their body before a tic. IA is also associated with anxiety.
In this project, we measured IA in a group of young people with TS/CTD and compared them to peers. We found that IA was reduced in young people with TS/CTD. Importantly, we also showed that it is possible to change IA with an instruction. IA was linked to anxiety within the TS/CTD group. This study is significant as it shows that we might be able to change IA with interventions and that IA is associated with tics and anxiety, so that’s really promising as a future treatment route.
What is attention bias, and what did you find out about how it affects people with Tourette’s?
There are differences between people in how they allocate their attention. Some people are much more aware of social threat, for example someone looking annoyed. This is associated with social anxiety and impairment (e.g. difficulties at school, making friends).
Here, we investigated whether young people with TS/CTD have this increased awareness of social threat. We found that young people with TS/CTD are more likely to pay attention to social threat, compared to their peers. We also found that this increased attention bias is linked with social anxiety and impairment. This is important as it begins to help us to understand why social anxiety is higher in young people with TS/CTD and possibly develop treatments to target this.
What difference do you think your research could make to people with Tourette’s in the future?
Understanding factors associated with anxiety and low mood in TS/CTD will allow us to develop more effective treatments. As a Clinical Psychologist, it has always been important to me that we offer the best evidence-based treatments to children and young people. However, there has been only limited research in TS/CTD. These projects are the first step in helping us understand what cognitive styles are important for anxiety and depression in TS/CTD. In the future, we can begin to think about how to target those processes in this group of people.