Half of cancer patients develop mental illness

A new study of nearly 290,000 Danes diagnosed with cancer between 1995 and 2015 shows that half developed anxiety, depression, or another mental illness within 25 years of their diagnosis, reports DR.

The risk is highest in the first year after diagnosis, with a fivefold increase in the likelihood of hospitalisation or medication for a mental disorder. After a decade, the risk remains 40% higher than in the general population.

Patients with the most severe cancers—such as pancreatic, brain, or liver cancer—face the greatest psychological strain, according to Christoffer Johansen, a cancer researcher and professor at the University of Copenhagen’s Department of Clinical Medicine, as well as a senior consultant at Rigshospitalet.

“Cancer is a disease you can die from, so the diagnosis can feel like a threat to life,” Johansen said. “It can trigger processes that lead to mental illness.”

The study, published in the British Journal of Cancer, compared cancer patients with a control group of about one million people matched by age, gender, and socioeconomic status. Among those without cancer, 33% of men and 39% of women developed a treatable mental illness or received medication for one.

Denmark’s latest national cancer plan includes measures to address post-treatment challenges, such as establishing late-effect clinics. However, Johansen doubts it will significantly ease the mental burden, noting that previous plans have also promised more psychological and social support—this time shifting responsibility to general practitioners.

“With nearly half a million cancer survivors, this becomes a massive task,” he said.