Traumatic events, post-traumatic stress disorder, and central sensitization in chronic pain patients of a German university outpatient pain clinic.

OBJECTIVE: Post-traumatic stress disorder (PTSD) and traumatic life events are often coupled to chronic pain; possibly linked by central sensitization. We wanted to assess the prevalence of traumatic events and PTSD in chronic pain patients of a German university hospital outpatient pain clinic. Moreover, we evaluated the extent of indicators and co-occurring traits of central sensitization in comorbid patients.

METHODS: We retrospectively divided 914 chronic pain patients into four groups depending on their trauma severity: no trauma, accidental trauma, interpersonal trauma, and PTSD. We collected electronic pain drawings focusing on pain area and widespreadness; as well as information about pain intensity, sleep impairment, disability, stress, anxiety, depression, and somatization. Differences between groups were calculated using Kruskal-Wallis with post-hoc Mann-Whitney tests.

RESULTS: Out of 914 patients, 231 (25%) had no trauma, 210 (23%) accidental traumas, 283 (31%) interpersonal traumas, 99 (11%) PTSD, and 91 (10%) could not be classified. We observed statistically significant differences between groups in pain area and widespreadness, as well as maximal pain, sleep impairment, disability, stress, anxiety, depression, and somatization. The severity of symptoms increased with trauma severity.

CONCLUSIONS: Traumatic life events and PTSD are frequent in chronic pain patients. The increased pain area and widespreadness, as well as the increased negative impact on co-occurring traits of sensory sensitivity (anxiety, depression, somatization), are compatible with central sensitization in comorbid patients. Therefore, a heightened awareness of the comorbidity between traumatic experiences and chronic pain is recommended.