Ires Ghielen

166 Chapter 9 elements from Acceptance and commitment therapy (ACT) with physical therapy. We compared the BEWARE training with group physical therapy. In chapter 8 we describe the results of this pilot RCT. Patients that participated in the BEWARE training showed no significant improvement in the primary outcome measure, self-efficacy, compared to the control condition. Patients that received the BEWARE training (more than patients that received physical therapy only) showed improved emotional wellbeing as well as standing balance, both at post-treatment and follow- up. Feelings of social stigmatization decreased in this group as well, however, this was not statistically significant. General reflection and clinical implications In chapters 2 and 3 , we describe the overlap between anxiety, depression, autonomic failure and motor dysfunction in different PD patient populations [1, 2]. Autonomic and motor symptoms were associated with the somatic subscales of the BAI, while depressive symptoms were associated with the affective subscale. The network analysis presented in chapter 4 also showed connections between symptoms of motor failure and anxiety. This gives rise to the question whether motor and (somatic) anxiety symptoms often co-occur, or that these items show overlap because they measure one and the same symptom. For example, somatic symptoms such as trembling and feeling unsteady can be interpreted both as motor symptoms of PD and as somatic equivalents of anxiety. This complicates diagnosing anxiety in PD, which can lead to either under- or overdiagnosis, since the somatic symptoms can both be interpreted as either PD-related or as anxiety-related. Within the explorative network analysis, the overlap between motor symptoms and somatic anxiety symptoms was present in both patient groups, in spite of the level of anxiety. This argues in favour of the hypothesis that the specific somatic anxiety and motor symptom scores represent one and the same symptom. To eliminate room for interpretation and measure anxiety without somatic equivalents, one could advise to solely use the 7-item affective subscale of the BAI that does not include motor aspects, as presented in chapter 2 and 3 [1, 2]. This subscale showed equal predictive value as compared to the total BAI in whether or not patients received an anxiety disorder diagnosis through psychiatric evaluation. However, despite of its equal predictive power, we do not recommend to disregard the somatic symptoms completely, as they are also an important part of anxiety [8]. The affective subscale might be useful as a first screening tool for anxiety in PD, to then interpret anxiety symptoms in the context of motor and autonomic symptoms. Chapters 2,3, and 4 described analyses on cross-sectional data, however, symptom fluctuations over time are very much apparent in PD patients. Over 65% of PD