1. Unraveling pathways to depression in fibromyalgia
Pinto AM1,2, Costa C1, Pereira AT2, Marques M2,3,4 Pereira da Silva JA1, Macedo A2,4
1 Clinica Universitária de Reumatologia, Faculty of Medicine and University Hospital of Coimbra, Portugal. 2Department of Psychological Medicine, Faculty of Medicine, University of Coimbra. 3Miguel Torga Higher Institute, Coimbra, Portugal. 4Centro de Responsabilidade Integrada do Serviço de Psiquiatria, University Hospital of Coimbra.
Correspondence to:
EPA 2016 Madrid, Spain March 2016
the role of perseverative negative
thinking and negative affect
Introduction
Several studies have demonstrated a strong link between fibromyalgia, negative affect (NA) and depression1,2. However, it remains unclear why some fibromyalgia patients get depressed while others do not and, primarily, which mechanisms account for this difference. We hypothesize that, besides clinical features, the engagement in dysfunctional strategies like perseverative negative thinking (PNT) followed by an amplification of NA levels may increase the risk of fibromyalgia patients experiencing depressive symptoms. Objective: To explore the serial mediator effect of PNT and NA on the relationship between fibromyalgia symptoms and depressive symptoms.
Methods
Participants and Procedure
103 women with fibromyalgia (Mean age 47.32±10.63) completed the Portuguese version of the following assessment tools.
Measures
Revised-Fibromyalgia Impact Questionnaire (FIQR3) encompasses 21 items that assess Function, Overall Impact and Symptoms of fibromyalgia. The Cronbach alphas were respectively .92, .83 and .83.
Perseverative Thinking Questionnaire (PTQ-154) consists of 15 items evaluating repetitive thinking and consequent cognitive interference/unproductiveness (CIU). The alphas of Cronbach obtained in this study were .96 for RT and .93 for CIU.
Beck Depression Inventory-II (BDI-II5) is one of the most used measures to assess depressive symptoms. Constituted by 21 items, it possesses a bifactorial structure. A total score, calculated through the sum of all items, was used in the present study (α=.93).
Profile of Mood States (PoMS6) assesses positive and negative mood states. A composite score representing negative affect was computed and used in the subsequent analyses. The Cronbach alpha for negative affect in this study was α=.95.
Analytic Strategy
The association between variables was investigated via Pearson correlations and Linear Multiple Regressions, using the SPSS, v Then, the variables that proved to be significant predictors were entered in a final serial multiple mediation model. This analysis was performed using PROCESS. Unconditional indirect effects were assessed via bootstrapping (5000 resamples).
Results (cont.)
Linear Multiple Regression
Table 2. Linear Multiple Regressions
Serial Multiple Mediation
CIU and NA as serial mediators between fibromyalgia symptoms and depressive symptoms
The estimated model, displayed in the figure above, was significant [F(3,86)=57.318, p<.001] explaining 66.66% of depressive symptoms variance. The total effect of fibromyalgia symptoms on depressive symptoms was of (SE=.0795, p<.001; CI =].3417 to .6578[), with a significant direct effect of (SE=.0653; CI = ],0614 to .3209[). The total indirect effects was of (SE=.0619; CI=].2033 to .4458[). Three significant specific indirect effects were found, namely: 1) an indirect effect of fibromyalgia symptoms on depressive symptoms via CIU (a1b1=.0764, SE=.0488; CI=].0012 to .1881[); 2) an indirect effect of fibromyalgia symptoms on depressive symptoms through CIU and NA (a1d21b2=.1207, SE=.0383; CI=].0638 to .2229[); 3) an indirect effect of fibromyalgia symptoms on depressive symptoms merely through NA (a2b2=.1115; SE=.0583; CI=].0111 to .2397[). Results suggest that those who report greater severity of fibromyalgia symptoms tend to engage more in perseverative negative thinking as a strategy to deal with them, which paradoxically generates/exacerbates NA, putting the individual at increased risk of experiencing depressive symptoms.
Model Summary
Function (FIQR)
Ov Impact (FIQR)
Symptoms (FIQR)
R2 Adj
F(df) p β t RT
.150
6.582 (3,92)
<.001
-.102
-.749NS
-.092
-.656NS
.532
3.831***
CIU
.268
(3,92)
-.153
-1.226NS
.057
.442NS
.588
4.622*** NA
.220
9.728 (3,90)
-.215
-1.584NS
.088
.644NS
.559
4.118***
BDI-II
Total
.347
(3,89)
-.157
-1.328NS
.278
2.206*
.487
4.068***
RT (PTQ15)
CIU (PTQ15) R2
.352
(2,92)
.200
1.292NS
.427
2.760**
.372
(2,91)
-.075
-.457NS
.685
4.166***
NA (PoMS)
.592
(1,91)
.772
11.602***
Note. * p<.05; ** p<.01; *** p<.001. NS: non-significant.
Cognitive Interference/
Unproductiveness
(PTQ-15)
Negative Affect
(PoMS)
Fibromyalgia Symptoms
(FIQR)
Depressive Symptoms (BDI-II)
b= .3983***(.0833)
b= ***(.3762)
b= .2005***(.0287) 
b= .3455***(.0909)
b= .7426*(.3298)
b= .2497* (.1179)
Results
Correlation Analysis
Table 1. Pearson Correlations between the variables under study
Variables 1 2 3 4 5 6
1. Function
(FIQR) -
2. Ov Impact
.661**
3. Symptoms
.662**
.683**
4. RT
(PTQ15)
.163
.198
.369**
5. CIU
.256*
.347**
.508**
.845**
6. NA
(PoMS)
.215*
.307**
.454**
.561**
.596**
7. BDI-II
Total score
.340**
.499**
.582**
.520**
.622**
.772**
Note: * p≤.05, **p≤.01.
Conclusion
The effect of fibromyalgia symptoms on depressive symptoms is partially operated through CIU, which in turn influences NA levels. Such findings highlight the crucial role of these constructs in the relationship between fibromyalgia symptoms and depressive symptoms and the urge to address them when treating individuals reporting greater fibromyalgia symptoms.
We are grateful to Andreia Fonseca for her contribution to this poster, with her amazing draw.
References : 1.Chang et al. Bidirectional association between depression and fibromyalgia syndrome: a nationwide longitudinal study. J Pain 2015; 16: Zautra et al. Examinations of chronic pain and affect relationships: Application of a dynamic model of affect. J Consult Clin Psychol, 2001; 69:786 – Bennett et al. The revised fibromyalgia impact questionnaire (FIQR): validation and psychometric properties. Arthritis Res Ther 2009; 11:R Ehring et al. The Perseverative Thinking Questionnaire (PTQ): Validation of a content-independent measure of repetitive negative thinking. J Behav Ther Exp Psychiatry 2011; 42:225– Beck et al. Manual for the Beck Depression Inventory-II. San Antonio, TX: Psychological Corp, McNair et al. Manual for the Profile of Mood States. San Diego, CA: Educational and Industrial Testing Service, 1971