In the US, about 13% of women and 10% of men aged 60 or older have knee pain due to osteoarthritis (OA). Osteoarthritis occurs when a joint becomes inflamed, usually because the protective cartilage and other tissues that cushion joints like the knee become damaged and worn over time. Knee pain from OA can make it harder to take care of yourself, which can damage your quality of life. In turn, that can lead to depression.

According to researchers, knee OA affects some 55% of people over age 40 in Japan. A research team from the country recently published a study in the Journal of the American Geriatrics Society, examining the effects of knee pain on depression since, until now, few studies have focused on how knee pain and impaired knee function relate to depression.

To learn more, the researchers examined information from 573 people aged 65 or older who participated in the Kurabuchi Study, an ongoing look at the health of older adults living in central Japan.

When the study began (between 2005 and 2006) none of the participants had symptoms of depression. Two years later, nearly all of them completed follow-up interviews. The participants answered questions about their knee pain and were evaluated for symptoms of depression.

Nearly 12% of the participants had developed symptoms of depression. People who experienced knee pain at night while in bed, while putting on socks, or while getting in or out of a car were more likely to report having symptoms of depression, noted the researchers.

The researchers concluded that asking older adults with knee pain whether they have pain at night in bed, when putting on socks, or while getting in or out of a car could be useful for helping to screen people at risk for developing depression.