By Pat Anson, PNN Editor

About 12 million people in the United States – nearly 5% of the adult population – have chronic pain that is accompanied by anxiety or depression so severe that it limits their ability to work, socialize and complete daily tasks, according to a new study.

The co-occurrence of chronic pain with anxiety and/or depression (A/D) is well known, but little research has been conducted on its prevalence or impact. To see how often the symptoms occur, researchers at the University of Arizona Health Sciences analyzed responses from nearly 32,000 people who participated in the 2019 National Health Interview Survey.

Their findings, published in in the journal PAIN, show that adults with chronic pain are about five times more likely to report anxiety or depression than those without chronic pain. The risk is even higher in adults with “high impact pain” – pain severe enough to limit daily life and work activities -- who are eight times more likely to have A/D.

"The study's findings highlight an underappreciated population and health care need -- the interdependency between mental health and chronic pain," said lead author Jennifer De La Rosa, PhD, director of strategy for the UArizona Health Sciences Comprehensive Pain and Addiction Center.

De La Rosa and her colleagues found that adults with co-occurring symptoms of pain, anxiety and depression had a significantly more disability compared to those with either chronic pain alone or A/D symptoms alone. Nearly 70% reported that their work was limited, about 44% had difficulty doing errands alone, and over half (56%) had problems participating in social activities.

"I was surprised by the magnitude of the effect with functional limitations," said De La Rosa. "Across all domains of functional activity in life, we saw an enormous jump among people who are living with both conditions. These are people who are at a high risk for functional limitation, which will disturb their quality of life."

Like pain, anxiety and depression are difficult to measure and clinicians have to rely on patients self-reporting their symptoms. Making a diagnosis is also difficult because chronic pain and A/D are interconnected neurologically, affecting the same parts of the brain that control cognition and emotional function. Anxiety and depression can heighten the perception of pain and may increase the likelihood of acute, short-term pain becoming chronic.

"When someone is experiencing both chronic pain and anxiety or depression symptoms, achieving positive health outcomes can become more challenging," said senior author Todd Vanderah, PhD, director of the Comprehensive Pain and Addiction Center. "This study gives us another avenue to explore in our continuing effort to find new ways to treat chronic pain."

Researchers say further studies are needed to see if people receiving pain treatment are also getting mental health care, and whether that care is helping with their symptoms.

A recent study found that anxiety, depression and other mood disorders often precede the development of fibromyalgia, irritable bowel syndrome (IBS), and chronic fatigue syndrome (CFS).