Depressed men with localized prostate cancer are more likely to be diagnosed with more aggressive prostate cancer and to get less effective therapies, according to a recent study.

Researchers from the University of California - Los Angeles found that depressed are more likely to be diagnosed with prostate cancer, receive less effective treatments and survive for shorter times than prostate cancer patients who were not depressed.

Prostate cancer is the most frequently diagnosed cancer in men aside from skin cancer. An estimated 233,000 new cases of prostate cancer will occur in the United States in 2014. Of those, nearly 30,000 men will die.

"Men with intermediate -- or high-risk prostate cancer and a recent diagnosis of depression are less likely to undergo definitive treatment and experience worse overall survival," Jim Hu, lead author of the study, said in a statement. "The effect of depressive disorders on prostate cancer treatment and survivorship warrants further study, because both conditions are relatively common in men in the United States."

Hu said the negative outcomes may be the result of several factors such as bias against the mentally ill, depression's impact on biological cancer processes, the depressed man's lack of investment in his general health and disinterest in receiving more effective care, and missed opportunities by physicians to educate patients about prostate cancer screening and treatment.

For the study, the research team collected data from 41,275 men diagnosed with localized prostate cancer between 2004 and 2007 and observed through 2009. Of those, researchers identified 1,894 men with a depressive disorder discovered in the two years before the cancer was diagnosed.

Based on the findings, men with prostate cancer who were older, had lower income, were white or Hispanic, who were unmarried and those residing in non-metropolitan areas were more likely to be depressed.

They also found that depressed men were less likely to seek out definitive therapy such as surgery or radiation in contrast to prostate cancers who were not non-depressed men.

"This was surprising, because depressed men were more likely to see physicians in the two years prior to prostate cancer diagnosis compared to non-depressed men," Hu said.

The findings were recently published in the online edition of the Journal of Clinical Oncology.