Psychiatric co-morbidities in patients with chronic peripheral neuropathic pain: a multicentre cohort study.

BACKGROUND: Psychiatric co-morbidities are common in patients with chronic pain, but no data are available about their prevalence in patients with neuropathic pain.

METHODS: A multicentre study involving neurology practices (n = 30) and pain departments (n = 8) was conducted to assess the prevalence of lifetime and current anxiety and mood disorders on the basis of DSM-IV criteria in patients with peripheral neuropathic pain. Factors independently associated with such co-morbidity were also studied. A total of 182 consecutive patients (age 59.5 ± 13.8 years, 48% men) were recruited. Assessments included lifetime and current anxiety and mood disorders (Mini International Neuropsychiatric Interview), sleep (Medical Outcome Study sleep scale), pain interference (Brief Pain Inventory) and catastrophizing (Pain Catastrophizing Scale).

RESULTS: Lifetime and current prevalence of psychiatric co-morbidity were 39% and 20.3%, respectively, for any anxiety disorder, and 47.2% and 29.7%, respectively, for any mood disorder. The two most common psychiatric disorders were generalized anxiety (current prevalence 12.1%) and major depressive episode (current prevalence: 16.5%). Logistic regression analyses showed that high catastrophizing was the most significant variable independently associated with both current anxiety (OR = 4.21[1.4-12.7]; p = 0.04) and mood disorders (OR = 6.9[2.2-21]; p < 0.001).

CONCLUSIONS: Lifetime and current anxiety and mood disorders are highly prevalent in patients with peripheral neuropathic pain, and are associated with high levels of catastrophizing. Early management of catastrophizing may contribute to reducing the risk of psychiatric co-morbidities in these patients.