It has long been thought that depression and anxiety increase the risk of developing cancer – although results have been inconclusive – but a recent analysis of multiple studies from the Netherlands, the United Kingdom, Norway and Canada suggests the theory might need more evidence and further research.
The analysis is published by Wiley online in CANCER, a peer-reviewed journal of the American Cancer Society.
Experts have thought that depression and anxiety may increase cancer risk by affecting a person’s health-related behaviours or by having biological effects on the body that support cancer development. Some research has supported an association between depression, anxiety and cancer incidence, while other investigations have found no or negligible associations.
To provide additional insights, Lonneke van Tuijl, PhD, of the University Medical Centre Groningen in The Netherlands and colleagues examined data from the international Psychosocial Factors and Cancer Incidence Consortium, which includes information from 18 prospective study groups with more than 300 000 adults from the Netherlands, the UK, Norway and Canada.
The team found no associations between depression or anxiety and overall, breast, prostate, colorectal and alcohol-related cancers during a follow-up of up to 26 years.
The presence of depression or anxiety was linked with a 6% higher risk of developing lung cancer and smoking-related cancers, but this risk was substantially reduced after adjusting for other cancer-related risk factors, including smoking, alcohol use and body mass index.
Therefore, this analysis supports the importance of addressing smoking and other unhealthy behaviours, including those that may develop as a result of anxiety or depression.
“Our results may come as a relief to many patients with cancer who believe their diagnosis is attributed to previous anxiety or depression,” said Van Tuijl. “However, further research is needed to understand exactly how depression, anxiety, health behaviours, and lung cancer are related.”
Study details
Depression, anxiety, and the risk of cancer: An individual participant data meta-analysis
Lonneke van Tuijl, Maartje Basten, Kuan-Yu Pan, Roel Vermeulen, et al.
Published in CANCER on 7 August 2023
Abstract
Background
Depression and anxiety have long been hypothesiSed to be related to an increased cancer risk. Despite the great amount of research that has been conducted, findings are inconclusive. To provide a stronger basis for addressing the associations between depression, anxiety, and the incidence of various cancer types (overall, breast, lung, prostate, colorectal, alcohol-related, and smoking-related cancers), individual participant data (IPD) meta-analyses were performed within the Psychosocial Factors and Cancer Incidence (PSY-CA) consortium.
Methods
The PSY-CA consortium includes data from 18 cohorts with measures of depression or anxiety (up to N = 319,613; cancer incidences, 25,803; person-years of follow-up, 3,254,714). Both symptoms and a diagnosis of depression and anxiety were examined as predictors of future cancer risk. Two-stage IPD meta-analyses were run, first by using Cox regression models in each cohort (stage 1), and then by aggregating the results in random-effects meta-analyses (stage 2).
Results
No associations were found between depression or anxiety and overall, breast, prostate, colorectal, and alcohol-related cancers. Depression and anxiety (symptoms and diagnoses) were associated with the incidence of lung cancer and smoking-related cancers (hazard ratios [HRs], 1.06–1.60). However, these associations were substantially attenuated when additionally adjusting for known risk factors including smoking, alcohol use, and body mass index (HRs, 1.04–1.23).
Conclusions
Depression and anxiety are not related to increased risk for most cancer outcomes, except for lung and smoking-related cancers. This study shows that key covariates are likely to explain the relationship between depression, anxiety, and lung and smoking-related cancers.
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