Sleep problems are common in cancer patients and are associated with significantly increased fatigue, pain, and depressed mood, according to a new study.

Dr. Edward J. Stepanski in Memphis, Tennessee, and his colleagues assessed links between difficulty sleeping and other symptoms in more than 11,000 cancer patients.

According to the researchers' report in the Journal of Clinical Sleep Medicine, more than half the patients reported trouble sleeping. About a quarter of them had moderate or severe trouble sleeping; this group was significantly younger and reported significantly more fatigue, pain, and depressed mood compared to those without trouble sleeping.

The effect of depressed mood on fatigue and physical pain was mediated by trouble sleeping, and the effect of trouble sleeping on fatigue was mediated by physical pain.

"Fatigue is a critically important symptom in patients with cancer, and these data suggest that effective treatment of depressed mood, trouble sleeping, and pain will improve fatigue," Stepanski, with the Accelerated Community Oncology Research Network, told Reuters Health.

"An intervention study aimed at optimizing treatment of depressed mood in cancer patients, with trouble sleeping, pain, and fatigue as outcome measures, is needed," he said.