The chemotherapy drug temozolomide, used to treat brain cancer, has the potential to increase depression, according to results of a study published in Translational Psychiatry.

Temozolomide is an antimitotic chemotherapy agent used to treat brain cancer, and in animal models of research, the agent used to decrease the growth of neurons in adults. Previous research indicates a connection between decreased neurogenesis and depression. Furthermore, depression tends to be underdiagnosed in patients with cancer.

In this study, mice were given temozolomide at a dose comparable to that used to treat brain cancer in adult humans.

One way to measure depression-like symptoms in mice is to assess how the animals process novelty. Mice given temozolomide experienced significant deficits in processing novelty. These mice also had significantly higher levels of the corticosterone stress response.

Researchers measured neurogenesis with a new approach to sectioning the brain so as to accurately differentiate dorsal and ventral neurogenesis. Results showed a significant correlation between decreased ventral neurogenesis and increased corticosterone response.

These results suggest a biological mechanism by which administration of temozolomide increases rates of depression; however, the researchers note that further research is needed.

Reference

1. Egeland M, Guinaudie C, Du Preez A, et al. Depletion of adult neurogenesis using the chemotherapy drug temozolomide in mice induces behavioural and biological changes relevant to depression [published online April 25, 2017]. Transl Psychiatry. doi: 10.1038/tp.2017.68.