A recent study has found that just more than 30 percent of people with cancer in Germany also experienced some form of clinically relevant mental health disorder.

The article, published earlier this month in the Journal of Clinical Oncology, found that 32 percent of people with cancer, or about one in three, had also experienced a clinically meaningful level of mental or emotional distress that met the strict criteria of one or more mental health disorders, such as anxiety, depressive or adjustment disorders. Study authors Mehnert et al. report that 42 percent of study participants with breast cancer had some sort of mental disorder. This was the highest prevalence among the 13 main types of cancer studied.

The article sheds new light on an area of study the authors say has had a considerable amount of research attention paid to it already. While past work has reported elevated levels of distress among people with cancer, Mehnert et al. write these studies vary in quality due to small sample sizes, different diagnostic criteria and assessment standards, and women with breast cancer being over-represented.

The authors write that the study results stress the need for psychological support for people with cancer, which could include psychotherapy, relaxation therapy and imagery. The American Cancer Society offers numerous resources for this kind of support.

Among the 2,100 study participants from cancer centers across Germany, the researchers found that 11 percent of patients had anxiety disorders, which was the most common type of disorder among study participants. The overall prevalence of mental health disorders was higher in those individuals with cancer (32 percent) than in the general population (20 percent) of Germany.

In general, the highest mental health disorder prevalence rates in study participants with cancer were found among those with breast cancer, head and neck cancer, and malignant melanoma. The lowest rates were found in patients with pancreatic cancer, stomach or esophageal cancer, and prostate cancer.

The work also brings to mind the importance of DNA sensitivity, or pharmacogenetic, testing for people with cancer. Certain cancer medications, such as the breast cancer treatment drug tamoxifen (Nolvadex), are metabolized by the body’s genetically variable CYP450 enzymes.

What’s more, many antidepressant and antipsychotic medications are processed by two CYP enzymes that demonstrate genetic variations: CYP2D6 and CYP2C19. Taking these medications in combination with cancer medications can lead to reduced effectiveness. But when there is genetic variation, the cumulative risk of problems may increase.

Learn more about pharmacogenetic testing here, and read more about the German study here.