Ires Ghielen

115 Meta-analyses on psychotherapies in MS and PD psychotherapy. Besides a primary focus on reducing psychological distress, we recommend to investigate the effect on coping with the disease, quality of life, valued living, or self-efficacy, especially in RCTs studying the effect of MBTs. Since progression of the disease is inevitable, it is therefore important to learn how to cope with the disease instead of focusing on symptom reduction only. Furthermore, caution is warranted in the choice of outcome measures and the type of control conditions as comparators, since these decisions greatly influence the study outcome. Lastly, it might be interesting to include executive dysfunction education in interventions for PD patients with impulse control disorders. Conclusion Despite the abovementioned limitations, we conclude that psychological interventions have a small to moderate effect on reducing psychological distress in patients with PD and MS. However, more research is warranted, especially in HD and PD patient samples. These studies need to have better methodological quality (e.g. lower risk of bias) and study samples should be larger to achieve a sufficient power. 6