Abstract:
Objective: Altered attentional processing (automatically attending to negative or illness-relevant information) and interpretative biases (interpreting ambiguous information as negative or illness-relevant) may be mechanistically involved in functional neurological disorder (FND). Common mechanisms between FND and chronic fatigue syndrome (CFS) have been proposed but not compared experimentally.
Methods: We compared cognitive task performance of FND, CFS and healthy control (HC) groups. Tasks assessed attentional bias towards illness-relevant stimuli (visual probe task), attentional control (attention network task) and somatic interpretations (interpretative bias task), alongside self-reported depression, anxiety, fatigue and general health.
Results: Thirty-seven participants diagnosed with FND, 52 participants diagnosed with CFS and 51 HC participants were included. Whilst participants with CFS showed attentional bias for illness-relevant stimuli relative to HC (t = -3.13 p = 0.002, d = 0.624), individuals with FND did not (t = -1.59, p = 0.118, d = 0.379). Both FND (t = 3.08, p = 0.003, d = 0.759) and CFS (t = 2.74, p = 0.007, d = 0.548) groups displayed worse attentional control than HC. Similarly, FND (t = 3.63, p < 0.001, d = 0.801) and CFS groups (t = 4.58, p < 0.001, d = 0.909) showed more somatic interpretative bias than HC.
Conclusions: Similar attentional control deficits and somatic interpretative bias in individuals with FND and CFS support potential shared mechanisms underlying symptoms. Interpretative bias towards somatic and illness-relevant stimuli in functional disorders may prove a therapeutic target.
Source: Keynejad RC, Fenby E, Pick S, et al. Attentional processing and interpretative bias in functional neurological disorder [published online ahead of print, 2020 Jun 12]. Psychosom Med. 2020;10.1097/PSY.0000000000000821. doi:10.1097/PSY.0000000000000821 https://pubmed.ncbi.nlm.nih.gov/32541544/