Depression, anxiety, health-related quality of life and pain in patients with chronic fibromyalgia and neuropathic pain

Chronic pain is often associated with comorbidities such as anxiety and depression, resulting in a low health-related quality of life. The mechanisms underlying this association are not clear, but a disturbance in the pain control systems from the brain stem has been suggested. Thirty neuropathic pain (NP) patients, 28 patients with fibromyalgia (FM), and 26 pain-free age- and gender-matched controls were included and examined with respect to mental distress (self-rated Symptom Checklist-92), depression (doctor-rated Hamilton Depression Scale and self-rated Major Depression Inventory), and anxiety (doctor-rated Hamilton Anxiety Scale and self-rated Anxiety Inventory). In addition, patients assessed their health-related quality of life (SF-36). Chronic pain patients with FM and NP had significantly more mental distress including depression and anxiety than healthy controls both by self-rating and by a professional rating. However, these scores are low compared to other studies on mental distress in chronic pain patients. Only few chronic pain patients meet the diagnostic criteria for depression (NP 3.3%, FM 7.1%), and associations between pain and mental symptoms were only found in the FM group despite similar pain intensities. The findings suggest that different mechanisms are responsible for the development of mood disorders in the two patient groups.