Study design: Prospective cohort with age- and gender-matched controls.
Objectives: To compare psychiatric morbidity between two groups: patients having chronic symptoms after a whiplash injury and patients who recovered completely.
Summary of background data: Psychiatric morbidity may influence the outcome of somatic diseases, and it has been suggested that psychological factors are often involved in the development of chronic symptoms after whiplash injuries, but there is no study assessing psychiatric morbidity in whiplash-associated disorder (WAD) using the Structured Clinical Interview for DSM-IV.
Methods: We studied a consecutive sample of 278 patients with a whiplash injury. Eighty-five had persisting neck pain after 1 year, and 38 of these participated in this study. For each patient with chronic neck pain at the 1 year follow-up, a gender- and age-matched recovered patient was selected from the study cohort of 278 cases. Psychiatric morbidity was determined using the Structured Clinical Interview for DSM-IV (SCID). The interview was conducted at 1 year after the accident (360 days, SD 2 days).
Results: The chronic WAD group had a significantly (P < 0.05) greater number of diagnoses 22 (58%) according to Axis I (acquired psychiatric disorders) than 11 (29%) the patients who were free of symptoms. This was also the case for Axis I diagnoses that were reported to have occurred before the accident (13 [34%]vs. 3 [8%]; P < 0.01). The most common diagnosis was depression; indeed, the number of patients with a history of depression at the time of the accident was significantly higher in the group who developed chronic pain compared to the group who recovered (11 [29%]vs. 3 [8%]; P < 0.05).
Conclusions: A history of psychiatric disease was more common in patients with chronic symptoms (chronic WAD). The dominating, retrospectively reported psychiatric diagnosis both before and after the accident was depression. Psychiatric morbidity may be a patient-related risk factor for chronic symptoms after a whiplash injury. The development of chronic symptoms after awhiplash injury seems to be associated with psychiatric vulnerability.