Fatigue and patterns of pain in fibromyalgia: correlations with anxiety, depression and co-morbidity in a female county sample.

This study explored the prevalence of fibromyalgia, the relationship of anxiety and depression with two major symptoms (pain and fatigue), and the role of co-morbidity. Participants were recruited from the Nord-Trøndelag Health Study (The HUNT Study) in Norway (N = 92,936). They were females given the diagnosis of fibromyalgia by their doctor (N = 1,816), divided into one sample without (N = 977) and another with (N = 839) co-morbidity. Owing to colinearity between anxiety and depression, extreme groups were defined according to high vs. low anxiety and depression scores. About four-fifths of the initial sample were excluded by this approach, which permitted a two x two factorial split-plot ANCOVA for the assessment of the relations of anxiety and depression with pain and fatigue. The overall prevalence was 3.2%, which obscured a highly biased sex difference with 5.2% for females and .9% for males. Results from the sample without co-morbidity (N = 977) supported the idea of independent partial correlations of anxiety and depression with pain and fatigue. A different trend was indicated in the co-morbidity sample (N = 839) where fatigue was only significantly associated with depression, whereas pain was associated with anxiety. The idea of widespread pain was supported consistently only in participants without co-morbidity who scored low on anxiety. Age, incident pain and depression contributed to a discriminant function reflecting the status of co-morbidity.

Quality of life, functional disability and lifestyle among subgroups of fibromyalgia patients: the significance of anxiety and depression.

This study explored the significance of anxiety and depression in quality of life, functional disability and lifestyle among fibromyalgia patients. Functional disability was defined by subjective work ability and activity-related discomfort. Lifestyle reflected habits of physical activity, regularity of meals, smoking and patterns of drinking coffee and alcohol. Members of two county divisions of fibromyalgia patients (N = 322) were investigated. Owing to colinearity between anxiety and depression scores, extreme groups were defined according to high vs. low anxiety and depression scores. Two-thirds of the initial sample were excluded by this approach which permitted a 2 x 2 factorial split-plot MANCOVA for the assessment of main effects and interaction of anxiety and depression upon quality of life, functional disability and lifestyle. Main effects of anxiety and depression were significant for index scores on activity-related discomforts, subjective work ability and quality of life, whereas depression was also significantly associated with regularity of meals. Anxiety and depression interacted to yield relatively high consumption of coffee and cigarettes among the anxious and depressed subgroup, and this effect emerged only after the elimination of confounding effects of age and duration of the fibromyalgia disease.

The role of anxiety and depression in fatigue and patterns of pain among subgroups of fibromyalgia patients.

This study explored the relationship of anxiety and depression with two major symptoms of fibromyalgia, pain and fatigue, among fibromyalgia patients (N = 322). Due to collinearity between anxiety and depression scores, extreme groups were defined according to high versus low anxiety and depression scores. Two-thirds of the initial sample were excluded by this approach, which permitted a two by two factorial split-plot ANOVA for the assessment of main effects and the interaction of anxiety and depression upon pain and fatigue. Results stated independent, additive, effects of anxiety and depression upon levels of pain and fatigue, whereas interaction between anxiety and depression failed to significantly explain symptom differences among the participants. Correlational analyses indicated widespread pain among the low anxiety subgroups. In contrast, widespread pain was not indicated among anxious patients with low scores on depression. The findings support the hypothesis that (1) anxiety and depression are independently associated with severity of pain symptoms in fibromyalgia, and that (2) patients with high anxiety and low depression may communicate to the medical doctor in ways that involve a risk of diagnosing fibromyalgia when the criterion of widespread pain is not supported. These conclusions were confirmed by results from ANCOVAs that permitted more extensive control of collinearity among variables.