Ires Ghielen

165 General discussion In Chapter 4 we used an explorative network analysis to study the associations between motor and anxiety symptoms, comparing symptom networks of high- anxious versus low-anxious PD patients. We investigated whether anxiety and motor symptoms are more strongly connected in the high-anxiety PD patient group, compared to the low-anxiety PD patient group [3]. The high-anxiety PD patient network showed higher global strength. In spite of group differences in which the high-anxiety group showed significantly worse motor and cognitive function, a higher age, and included more female patients, the network comparison test showed a significant difference in global strength, but did not show statistically significant differences in strength of the connections between motor and anxiety symptoms between the patient groups. Chapters 2,3, and 4 focused on the associations between motor, anxiety, and other symptoms, not taking into account their temporal relationships. In chapter 5 , we investigated the longitudinal associations between anxiety, fear of falling, and freezing of gait in 153 PD patients [4]. Across 4 measurements, with three weeks between each measurement, all associations were significant, with the strongest association between fear of falling and freezing of gait. Adjustments for disease characteristics and adverse effects of medication diminished all associations. After a description of the phenomenology of anxiety, and its cross-sectional and longitudinal associations with motor and other non-motor symptoms, part 2 of this PhD thesis focusses on the treatment of these complex symptom interactions in PD patients. In chapter 6 , we describe two meta-analyses on the effects of cognitive behavioral and mindfulness-based therapies on psychological distress in patients with neurodegenerative disorders [5]. The included studies were divided in those comparing the treatment of interest with an active control condition and those with a treatment as usual or waitlist control condition. The results showed that psychological interventions have a small to moderate effect on reducing psychological distress in patients with PD and Multiple Sclerosis (MS). The overall quality of the included studies was low and showed considerable heterogeneity. No evidence was found for publication bias. Chapters 7 & 8 present the study protocol and results of a pilot randomized controlled trial (RCT) in which we described and investigated a newly developed multidisciplinary group treatment for wearing-off related anxiety in PD named BEWARE [6, 7]. BEWARE is a body awareness group training in which we combine 9