Psychological therapies, such as cognitive behaviour therapy (CBT) are first-line treatments for the most common mental health problems, namely anxiety and depression (National Institute for Care and Excellence, 2009), and yet they are only partially effective. For example, similar to anti-anxiety/antidepressant medications, approximately half of individuals do not experience a significant improvement in their symptoms after CBT (DeRubeis et al., 2005; Loerinc et al., 2015). A common, and very important question that we are often asked is: how can genetic studies help inform psychological therapy? For many people, it makes sense that genetic information might be valuable towards improving medical treatments. However, some find it more difficult to understand how genetics might also be valuable for improving psychological therapies. We believe genetic studies have the potential to help improve psychological therapy outcomes, and here we will explain how.
Predicting treatment response
So, we know that not everyone responds well to CBT, or any other psychological therapy for that matter. No single treatment works for everyone. The field of research called precision medicine (or personalised medicine) recognises this and is specifically focused on identifying factors that predict response to different treatments, be it chemotherapy or anti-depressants. Once we know which factors are associated with better or worse outcomes following treatment A versus treatment B, we can use these factors in personalised medicine prediction strategies. These tools will help doctors to prescribe the course of treatment that is most likely to be effective for each person.
Therapygenetics refers to the prediction of outcomes following psychological therapy using genetic markers. The notion that differences in our genetic makeup can influence our likelihood of responding to a psychological therapy might seem odd at first. However, when you think about the widespread effects of genes on our biology (e.g neurochemical factors), our behaviour, or the likelihood of us developing depression or anxiety in the first place, it doesn’t seem so surprising.
This work is still very new but there is early evidence that genetic factors are associated with treatment outcomes. For example, a study of children with anxiety disorders found that genes associated with how much someone is affected by their environment (their ‘environmental sensitivity’) actually influenced response to CBT. In fact, this genetic information indicated that those who were more sensitive to their environment benefited the most from more intensive treatments, whereas for those who were not genetically sensitive to their environment, it didn’t matter as much which type of treatment they received (Keers et al., 2016). Another recent study of adults with depression found that genetic factors associated with autism predicted less favourable outcomes following CBT (Andersson et al., 2018). This could plausibly be because of communication difficulties associated with autistic traits, which might impact how well people can engage with their treatment. This work is very preliminary and needs to be replicated before we can start to draw any strong conclusions. However, it demonstrates the potential utility of genetic information in understanding how patients respond to psychological treatments.
Understanding processes underlying recovery
If we can start to identify genes that are strongly associated with treatment response, we can then think about the biological processes involved in recovery. Furthermore, we may highlight specific genes that interact with our environment (because that’s what psychological therapy is – a positive environmental experience). These discoveries could also shed light on the biological mechanisms involved in the development of anxiety and depression. We hope that all of these clues collectively will play a vital role towards our understanding of anxiety and depression and help us to develop better treatments.
Therapygenetics studies require large numbers of participants who have received, or are about to receive, psychological therapy for a mental health problem. One of the aims of the GLAD Study is to identify predictors of treatment response, by asking participants about their experiences of treatment and recruiting individuals who are undergoing therapy in an NHS service. We can then use their saliva samples (containing their genetic information; see our recent blog on what we can and cannot do with your samples) to investigate how genetic factors influence response to treatment, alongside other clinical and demographic factors. This work is in its early stages, but we’re hopeful it can really make a difference to how treatments are allocated – to help doctors know which treatment is most likely to work for whom, and hopefully why!