Cognitive behavioural therapy: we discovered a data gap on its effectiveness for different ethnic groups

Cognitive behavioural therapy (CBT) is one of the most common treatments for many different mental health conditions. This talking therapy aims to help people by identifying unhelpful thoughts and patterns of behaviour and promoting new ways of thinking. It’s used to treat a variety of common conditions, such as anxiety and depression – and is even used to help manage physical health conditions, such as chronic pain, cancer and diabetes.

CBT is also the most researched psychological therapy in the world. Once it was shown to be helpful for one condition, researchers began testing it across many others. But though plenty of time, money, and resources have been put into investigating the effectiveness of CBT, our recent study has shown that only a small proportion of the research is known to have included data from non-white ethnic groups. This means we may not fully know if CBT actually does work equally well for people from different ethnic groups, religions and cultural groups.

The full picture

To better understand how effective CBT is, we conducted a “panoramic meta-analysis”, which pooled results from multiple meta-analyses (a study which combines data from multiple studies) on CBT. This allowed us to get a fuller picture of the research, and see whether CBT works. This also allowed us to look at data from many more participants than a single study might have. This method also allowed us to understand if CBT improved everyone’s quality of life, or if it only worked for people suffering from certain conditions (such as depression and anxiety).

Our panoramic meta-analysis pooled data from 24 meta-analyses, representing 49 randomised control trials and data from 4,304 participants. We found CBT consistently improves quality of life across 12 different health conditions, including addiction, anxiety, fatigue, musculoskeletal disorders, and post-traumatic stress disorder. It was also effective regardless of age, and worked just as well when performed online as face-to-face.

However, only 11 of the 49 randomised control trials included in our panoramic meta-analysis reported the ethnicity of participants. Of the 4,304 participants, we found 1,577 were white, 237 were black, 34 were Asian, two were Chinese, and 26 were classified as mixed ethnicity or “other”. There may have been more people from each ethnic group represented in the research but this was not reported for 2,428 participants.

Although research guidelines are encouraging researchers to reduce bias and increase transparency by reporting on the characteristics of the participants, our study showed that few recent studies are doing this.

Ethnicity and culture

Research findings are often used to make decisions on what services should be offered to people with a certain health condition. But if the research is based on findings primarily from just one ethnic group, can we really offer the therapy to people from all the other ethnic groups? Without data from all ethnic groups, it also makes it uncertain if the treatment will be as effective for people of some ethnic backgrounds compared to others.

A concern is that there is hesitancy among some non-white ethnic groups about participating in health research. This hesitancy may partly stem from bias in the method researchers use to sample participants for their studies. It may also come from belief systems certain groups may have that prevent them from participating in scientific research. But this lack of participation may in turn lead to mistrust in medical research by some non-white ethnic groups due to under-representation. A person’s cultural background may also affect whether they participate in health research.

In the UK, 28% of funding for psychological research is dedicated to CBT. Although CBT is shown to work for a variety of conditions (including anxiety, depression, and even back pain), the amount of money still spent on researching it could be at the expense of exploring other psychological therapy options – especially options for those who don’t benefit from CBT.

Evidence also suggests that people from non-white ethnic groups are less likely to access and more likely to leave CBT services. However, it’s currently unclear why this is the case.

Medical systems are based on evidence-based, risk-balanced decisions. The evidence for CBT as an effective treatment is very powerful, which is why people are more likely to fund and use CBT rather than other less well-researched therapies.

But is that evidence actually reliable? As our review showed, non-white ethnic groups are still very under-represented in CBT research so we don’t really know whether CBT will be as effective for people from different ethnic groups and cultural backgrounds.

People from different ethnic backgrounds may also have certain cultures, religions, and social norms that may influence whether they seek help for health problems. Examining ethnicity will be important for future research to better understand who CBT is useful for – and what impact culture and religion may also play in its effectiveness.

Beth Fordham receives funding from the National Institute of Health Research Health Technology Assessment.