Date Published: April 5, 2017
Publisher: Public Library of Science
Author(s): Beatrice Heim, Marie-Theres Pertl, Ambra Stefani, Margarete Delazer, Anna Heidbreder, Laura Zamarian, Elisabeth Brandauer, Klaus Seppi, Birgit Högl, Werner Poewe, Atbin Djamshidian, Raffaele Ferri.
To investigate decision making in patients with primary restless legs syndrome (RLS) with and without augmentation treated with dopaminergic medication.
A total of 64 non-demented RLS patients treated with dopaminergic medication with and without augmentation were included in this study. We used an information sampling task to assess how much evidence participants gather before making a decision. Performance was compared to the results of 21 healthy controls.
All patients with and without augmentation gathered less information than healthy controls before making a decision (p<0.001), but there was no difference between the two patient groups (p = 1.0). Furthermore, both patient groups made more irrational decisions (e.g. decisions against the evidence they had at the time) than healthy controls (p≤0.002). In addition, RLS patients with augmentation made significantly more irrational decisions than RLS patients without augmentation (p = 0.037) and controls (p<0.001). Our results show that RLS patients treated with dopaminergic drugs, regardless of having augmentation or not, jumped to conclusions and decided significantly more often against the evidence they had at the time of their decision. However, those with augmentation performed worse than all other groups and made more often irrational decisions, a phenomenon which is also common in patients with substance abuse or behavioural addictions. Thus, jumping to conclusions and deciding with a higher degree of uncertainty as well as irrational decision making is more common in RLS patients treated with dopaminergic medication particularly in those with augmentation.
Restless legs syndrome (RLS) is a common sensorimotor disorder, which is frequently associated with neuropsychiatric comorbidities such as depression or panic disorder [1,2]. Dopaminergic drugs, especially non-ergot-derived dopamine agonists and alpha-2-delta ligands are considered as first-line therapies . However, dopamine agonists may cause side effects such as impulse control disorders (ICDs) [4,5], augmentation or both [6–8] in a subgroup of treated patients.
The study was approved before initiation by the local Ethics Committee of the Medical University of Innsbruck, Austria, and all participants provided written informed consent according to the declaration of Helsinki.
Results of demographic and clinical variables of RLS patients with and without augmentation are shown in Table 1.
This is the first study to assess jumping to conclusion behaviour in RLS patients with and without augmentation. We found that both patient groups gathered significantly less information and made more irrational decisions, e.g. deciding against the evidence they had at the time of their decisions, than healthy controls.
We found that both RLS patient groups jumped to conclusions and made more decisions against the evidence on the beads task than healthy controls. Furthermore, patients with augmentation made significantly more often irrational decisions than controls and RLS patients without augmentation. This behaviour is often seen in patients with substance abuse [18,20], patients with schizophrenia  and those with behavioural addictions [20,39]. Whether this trait is also found in RLS patients treated with alpha-2-delta ligands needs to be explored in future studies.