The Relationship Between Level of Catastrophizing and Mental Health Comorbidity in Individuals With Whiplash Injuries

OBJECTIVES Pain catastrophizing has been shown to be correlated with measures of mental health problems such as depression and post-traumatic stress disorder (PTSD). However, the clinical implications of findings reported to date remain unclear. To date, no study has been conducted to determine meaningful cut-scores on measures of catastrophizing indicative of the heightened risk of mental health comorbidity. One objective of the present study was to identify the cut-score on the Pain Catastrophizing Scale (PCS) indicative of the heightened risk of the comorbidity of depression and PTSD. A second objective was to determine whether mental health comorbidity mediated the relationship between catastrophizing and occupational disability. MATERIALS AND METHODS The sample consisted of 143 individuals with whiplash injuries. Pain severity, pain catastrophizing, depression, and post-traumatic stress symptoms were assessed after admission to a rehabilitation program. Mental health comorbidity was operationally defined as obtaining a score above the clinical threshold on measures of depressive and/or post-traumatic stress symptom severity. RESULTS A receiver operating characteristic curve analysis revealed that a PCS score of 22 best distinguished between participants with and without mental health comorbidity. Results also revealed that mental health comorbidity mediated the relationship between catastrophizing and occupational disability. DISCUSSION The findings suggest that a score of ≥22 on the PCS should alert clinicians to the possibility that patients might also be experiencing clinically significant symptoms of depression or PTSD. Greater attention to the detection and treatment of mental health conditions associated with whiplash injury might contribute to more positive recovery outcomes.