Contents lists available at ScienceDirect Journal of Obsessive-Compulsive and Related Disorders journal homepage: www.elsevier.com/locate/jocrd Neuropsychological functioning in pediatric obsessive-compulsive disorder: One size does not fit all Blanca Garcia-Delgar a , Elena de la Serna b , Sara Lera a , Eva Varela a , Susana Andrés-Perpiñá a,b,c , Luisa Lázaro a,b,c,d, ⁎ a Department of Child and Adolescent Psychiatry and Psychology, Institute of Neurosciences, Hospital Clínic Universitari, c/Villarroel 170, Section 9 Floor 2, 08036 Barcelona, Spain b Centro de Investigación en Red de Salud Mental (CIBERSAM), Instituto Carlos III, Spain c Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain d Department of Medicine, University of Barcelona, c/ Casanova 143, 08036 Barcelona, Spain ARTICLE INFO Keywords: Neuropsychology Obsessive-compulsive disorder Children and adolescents Cluster analysis ABSTRACT Previous studies examining neuropsychological functioning in pediatric obsessive-compulsive disorder (OCD) have presented heterogeneous results. To clarify if this variability could be related to the existence of discrete cognitive profiles, we conducted a cluster analysis to identify homogeneous groups of patients with similar neuropsychological performance in a sample of 61 children and adolescents with OCD. Then, each OCD group was compared to a matched control sample (n=40) with regard to their neuropsychological variables. Finally, demographic and clinical comparisons were conducted to investigate differences between the OCD groups. A two-cluster solution was identified. The first group (n=52, 85%) performed comparably to controls in all neuropsychological domains (“preserved”) whereas the second group (n=9, 15%) exhibited a poorer perfor- mance than controls in non-verbal memory (p < 0.01) and visuospatial abilities (p < 0.01). Contrary to our expectations, the two OCD groups did not differ in demographic and clinical variables. These findings support the presence of at least two cognitive profiles in children and adolescents with OCD, and begin to address the relationship between these discrete groups and clinical and functional factors. 1. Introduction Obsessive-compulsive disorder (OCD) is a psychiatric condition characterized by obsessions (intrusive unwanted thoughts, images or urges) and/or compulsions (repetitive behaviors or mental acts per- formed to relieve the distress caused by obsessions) (American Psychiatric Association, 2013). The disorder has a lifetime prevalence of 2.3% (Ruscio, Stein, Chiu, & Kessler, 2010) and can cause significant impairment to both affected individuals and family members (Stewart et al., 2017). Once considered to be rare in the pediatric population, it is currently known that the first symptoms of the disorder may appear during childhood or adolescence (Delorme et al., 2005). OCD has been associated with deficits in neuropsychological functioning that seem to play a role in the development of obsessive-compulsive (OC) symptoms (Nakao, Okada, & Kanba, 2014). In contrast to the extensive literature on neuropsychology in adults with OCD (Abramovitch, Abramowitz, & Mittelman, 2013), studies in the pediatric population are scarce and have reported heterogeneous results. First, it is still unclear whether youth with OCD exhibit some degree of underperformance in neuropsychological functioning com- pared to controls. Although most studies in pediatric OCD have re- ported deficits in certain neuropsychological domains (Andres et al., 2007; Behar et al., 1984; Chang et al., 2007; Geller et al., 2017; Ornstein, Arnold, Manassis, Mendlowitz, & Schachar, 2010; Shin et al., 2008; Taner, Baker, & Oner, 2011), some others have failed to identify statistically significant differences in neuropsychological functioning between the two groups (Beers et al., 1999). More recently, Abramovitch et al. (2015) conducted a meta-analysis on pediatric OCD studies that also provided evidence of similar neuropsychological per- formance in youth with OCD compared to controls. Second, data on the neuropsychological domains that may be af- fected in pediatric OCD are also inconclusive. On the one hand, it has been suggested that executive functions such as set shifting or cognitive flexibility may be among the most impaired areas in youth with OCD (Ornstein et al., 2010; Shin et al., 2008; Taner et al., 2011). However, other studies have not found statistically significant differences be- tween youth with OCD and controls in neuropsychological tests asses- sing this domain (Beers et al., 1999; Chang et al., 2007, Geller et al., https://doi.org/10.1016/j.jocrd.2017.12.005 Received 18 August 2017; Received in revised form 6 December 2017; Accepted 8 December 2017 ⁎ Corresponding author at: Department of Child and Adolescent Psychiatry and Psychology, Hospital Clínic Universitari, c/ Villarroel 170, Section 9 Floor 2, 08036 Barcelona, Spain. E-mail address: LLAZARO@clinic.ub.es (L. Lázaro). Journal of Obsessive-Compulsive and Related Disorders 16 (2018) 36–42 Available online 13 December 2017 2211-3649/ © 2017 Elsevier Inc. All rights reserved. T