“…In contrast to the lack of clusters in our motor FND group of patients, previous high-quality studies using the same methodology (gap statistics) reported homogeneous clusters including drug-naive parkinsonism (Jain, Park, & Comer, 2015), comorbidities associated with obesity (Reategui, Ratte, Bautista-Valarezo, & Duque, 2019), breast cancer progression data (Alexe, Dalgin, Ganesan, Delisi, & Bhanot, 2007). However, most cluster analysis studies in neurological conditions with motor symptoms such as Parkinson's disease (Ba, Obaid, Wieler, Camicioli, & Martin, 2016; Mu et al, 2017; Yang, Kim, Yun, Kim, & Jeon, 2014) or fibromyalgia (Yim et al, 2017) suffered from important methodological problems which could have led to false-positive cluster identification.…”