It’s not clear what to make of this study.
Breast cancer patients who use alternative methods to recover from chemotherapy or surgery are more often depressed than those who do not receive alternative treatment.
The study is unique, since it focuses on how a large and representative sample of 3,000 patients from across Denmark experience the effects of alternative treatment.
“We’re very surprised at the results. This is directly contrary to our assumption that cancer patients who receive alternative treatment would get some form of relief that made them less likely to get depressive symptoms,” says Christiana Gundgaard Pedersen, a postdoc fellow at the Department of Psychology and Behavioural Sciences, Aarhus University, Denmark.
“Our study shows that users of alternative treatment experience far more depressive symptoms for more than a year after the completion of the cancer treatment, compared with those who did not receive alternative treatment.”
”Dietary supplements are the primary culprit. Here we observed a significant difference: those who took dietary supplements experienced a particularly high degree of depressive symptoms,” says the researcher.
Previous studies have shown that a plant known as Hypericum, which is frequently used in natural remedies for depression, has a negative effect on the efficacy of chemotherapy. Cancer patients are therefore advised not to use the plant to treat depressive symptoms.
What is the connection? We have a correlation shown but not causation. Causation is much harder to prove because all confounding factors must be controlled which is extremely hard to do. This is why we don’t have many causation studies in humans. It can be unethical to control for all factors and typically impossible. So, we have to look for correlations and do several studies. This is just one so it’s not clear what it means.
Tip: Thomas Proffit