Patients who are diagnosed with cancer can experience significant emotional distress. Now a study has shown that anxiety and depression may increase mortality among patients who have advanced lung cancer.

The study, “Anxiety After Diagnosis Predicts Lung-Cancer Specific And Overall Survival In Patients With Stage III Non-Small Cell Lung Cancer,” was published in the Journal of Pain and Symptom Management by researchers from The University of British Columbia.

“The question of whether anxiety and depression affect survival in cancer patients has been of interest to scientists for decades, but long-term research has been limited,” Andrea Vodermaier, PhD, the study’s first author, said in a press release. “Our study confirms that there is indeed a link for lung cancer patients, and that it’s important for healthcare providers to treat not only their tumor but also focus on the full emotional experience of the patient,” she said.

The research enrolled 684 patients who had been diagnosed recently with stage III non-small cell lung cancer (a type of lung cancer with survival rates of only 30-46% after one year). Patients were continuously assessed for anxiety and depression using the PsychoSocial Screen for Cancer (PSSCAN) questionnaire, both after diagnosis and before treatment start.

Patients who experienced increased anxiety and depression had poorer survival rates than those who didn’t. It was not clear, however, whether these factors have a direct impact on survival, or rather act by influencing other psychosocial factors.

“It is likely that other unmeasured factors that correlate with high anxiety and depression, such as less social support, could play a role,” said the study’s senior author, Robert Olson, MD. “However, the relationship that we found is significant, and certainly worth further exploration into whether interventions to improve anxiety and depression in lung cancer patients can improve survival rates.”

One of the study’s limitations is that it included no data on whether patients continued smoking or couldn’t quit after being diagnosed with lung cancer, which can affect their levels of anxiety and depression.

“Because emotional distress is associated with continued smoking and lack of success of smoking cessation attempts, psychological interventions potentially could influence length of survival in lung cancer patients,” researchers wrote in the study.