The relationship between pain and depression in multiple sclerosis.
|Title||The relationship between pain and depression in multiple sclerosis.|
|Publication Type||Journal Article|
|Authors||Askew RL, Amtmann D, Kim J, Chung H, Johnson KL|
|Journal||International Journal of MS Care|
|Psychological issues and MS, Quality of Life in MS|
Background: The relationship between pain and other aspects of psychological functioning in multiple sclerosis (MS) has not been well studied. Objectives: In this study we examined whether fatigue, anxiety, and sleep disturbances mediate the effect of pain impact on depression. Methods: A total of 1245 members of the National Multiple Sclerosis Society completed surveys. Two scales were used to assess pain interference: the Brief Pain Inventory (BPI) and the Pain Impact Questionnaire (PIQ); three scales assessed fatigue: the Modified Fatigue Impact Scale (MFIS), the Fatigue Severity Scale (FSS), and the Multidimensional Assessment of Fatigue (MAF); two scales assessed depression: the Center for Epidemiologic Studies Depression Scale (CES-D) and the Patient Health Questionnaire (PHQ-9); two scales assessed sleep: the Medical Outcomes Survey (MOS-SAD) and the Women’s Health Initiative Insomnia Rating Scale (WHIIRS); anxiety was assessed by the Hospital Anxiety and Depression Scale (HADS). The model was controlled for age, gender, disability status, and level of social support. Results: Standardized factor loadings were moderate to high for fatigue (FSS = 0.83, MFIS = 0.90, MAF = 0.86), sleep disturbance (WHIIRS = 0.66, MOS-SAD = −0.73), pain impact (PIQ = 0.88, BPI = 0.92), and depression (CES-D = 0.94, PHQ-9 = 0.91), and all were statistically significant. All standardized direct effects were statistically significant, including pain interference on anxiety (0.51), on fatigue (0.56), and on sleep disturbance (0.63); anxiety on depression (0.39); sleep disturbance on fatigue (0.21) and on depression (0.22); and fatigue on depression (0.45). Standardized indirect effects of pain interference on depression totaled 0.65. Variance explained (R 2 ) ranged from 0.21 to 0.79 (pain interference = 0.21, anxiety = 0.33, fatigue = 0.57, sleep disturbance = 0.40, and depression = 0.79). Model fit was adequate (χ 2 = 343.3 [df = 49], P < .05, RMSEA = 0.069, CFI = 0.965, TLI = 0.939, SRMR = 0.033). Conclusions: The majority of the effects of pain interference on depression were mediated by anxiety, fatigue, and sleep disturbance, which could have important implications for clinical management and ongoing investigations. Results suggest a transdiagnostic approach to treatment that may be more effective than depression treatment alone or pain treatment alone.