Comorbid symptoms in fibromyalgia (FM) syndrome, such as mood disorders and cognitive dysfunction, may lead to greater functional impairment than pain itself. This study aimed to unravel the modulating role of depression in response execution and inhibition in FM using an emotional go/no-go task.
In total, 17 FM patients with low depression, 18 FM patients with high depression, and 18 pain-free controls were included. Pain, happy, and neutral faces were pseudorandomly presented, and participants were asked to respond to male faces (go trials) by pressing a button, and to inhibit their responses if female faces were presented (no-go trials).
FM patients with high depression showed lower positive affect scores, higher negative affect and pain vigilance scores, and slower reaction times, than FM patients with low depression and pain-free controls. Both subgroups of FM patients also rated pain faces as more arousing than pain-free controls. The lack of group differences in our electrophysiological data, neither in N200 nor in P300 amplitudes, seems to indicate that there was no significant impairment in response execution in response inhibition due to pain.
Taken together, these results add evidence to the notion that depression is associated with higher affective dysregulation and deficit of information-processing speed in FM. Furthermore, our data suggest that pain induces a bias to pain-related information, but the absence of significant group differences in event-related potential amplitudes, calculated with analyses of covariance (ANCOVA) (with pain intensity), seem to show that pain intensity is not a predictor for cognitive dysfunctions.
*Research Institute of Health Sciences (IUNICS), University of Balearic Islands (UIB)
†Balearic Islands Health Research Institute (IdISBa), Spain
‡Institute of Psychology, University of Health Sciences Medical Informatics and Technology (UMIT), Austria
C.S. and A.M.G.-R. are co-first authors.
Supported by the Spanish Ministry of Economy, Industry, and Competitiveness (MINECO) (grants #PSI2010-19372, #PSI2013-48260-C3-1-R, #PSI2015-66295-R, #PSI2016-78637-P, AEI/FEDER,UE) and La Marató de TV3 (grant #070110, Spain). The authors declare no conflict of interest.
Reprints: Carolina Sitges, PhD, Research Institute of Health Sciences (IUNICS), University of Balearic Islands (UIB), Cra. de Valldemossa km 7.5, Palma 07122, Spain (e-mail: email@example.com).
Received September 8, 2017
Received in revised form June 15, 2018
Accepted June 21, 2018