Previous research has established that people with pre-existing mental health conditions may not take up cancer screening opportunities as often as other groups in the community and that they have a comparatively higher risk of dying from a range of health conditions.

However, there has yet to be a systematic review of how the cancer treatment received is impacted by a person’s pre-existing mental health disorder. The scope of conditions includes schizophrenia, bipolar disorder, depression, and anxiety of differing severity.

A new study, led by PhD student Yueh-Hsin Wang with Dr Ajay Aggarwal, Professor Robert Stewart, and Dr Elizabeth Davies, sought to address this gap in knowledge by doing a systematic review of articles on the topic from 1995 to May 2022.

The analysis of 29 studies found clear evidence of disparities in the receipt of guideline recommended cancer treatments for those with pre-existing mental health disorders.

This was consistent across a broad range of cancer types, as well as different methods of treatment including surgery, radiotherapy, and chemotherapy.

These results highlight the issue of disparities within cancer treatment for individuals with pre-existing mental health disorders and the authors hope that will raise awareness of the issue within a research and public health context.

There has been little research on the relationship between mental health disorders and cancer treatment. The authors say that more research is needed on how these conditions may impact on delays in cancer treatment, how they may affect a person’s adherence to treatments prescribed by clinicians, and on the less commonly studied rare cancers that affect areas such as the central nervous system, skin, and haematological systems.

Alongside such considerations, the results showed that the research that does exist predominantly focuses on people in high income countries and is of a quantitative nature. The authors suggest that more research should be conducted on individuals living in low-to-middle income countries and employ qualitative interview methods.

More qualitative research would be beneficial, particularly in understanding the individual perspectives of people undergoing cancer treatments and healthcare professionals as well as comparing experiences of cancer treatment within and between different national healthcare systems.