Chronic pain and depression are among the most disabling conditions worldwide, and many people struggle with both.

"About half the people with depression have some pain symptoms, and about half the people with pain have some depression symptoms,” Kurt Kroenke, a research scientist at the Regenstrief Institute, said.

This can cause a vicious cycle. For example, people dealing with pain often don't sleep well.

It affects their mood, which can make them vulnerable to depression or anxiety.

It can also increase a person's susceptibility to pain.

“Anybody who's suffered from chronic pain knows that it just takes over, and the same with depression,” Kroenke said.

Kroenke said when someone visits a doctor for chronic pain, it's important for the patient to discuss any psychological symptoms they're also having.

“In particular, trouble sleeping, no energy, trouble concentrating,” Kroenke said.

Kroenke is the creator of several widely used questionnaires that help doctors easily measure severity of pain, depression or anxiety. He says it's important to identify and treat both and end the negative cycle.

When someone is dealing with both pain and depression, treating one can sometimes help lower the symptoms of the other. In other cases, a combination of treatments might be needed.

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