Patients with COPD demonstrated gray matter decreases in areas of the brain that process breathlessness, fear and sensitivity to pain. The study found patients with COPD show regionally decreased gray matter volume in the anterior, mid, and posterior cingulate cortex, hippocampus, and amygdala. Levels of degeneration in certain areas of the brain were also impacted by longer disease duration. Those individuals showed a greater fear of breathlessness and fear of physical activity, which can affect the course of the disease.