A recent study measured mental health and physical performance (walking) in patients with chronic low back pain. Patients who had poor mental health reported the same amount of pain before and after the walking tests as other patients. They also walked the same amount of time.
Patients who scored low on mental health were more likely than others to stop walking because of pain. But pain–not mental health–was the main factor that stopped patients from walking. This suggests that depression and anxiety may come from (rather than cause) poor physical performance in patients with low back pain.
Optimal treatment for patients with low back pain addresses all of these issues, mental and physical, to get the best results.