Review ArticleEndophenotypes of executive functions in obsessive compulsive disorder? A meta-analysis in unaffected relativesZartaloudi, Eirinia; Laws, Keith R.b; Bramon, ElviraaAuthor Information aDivision of Psychiatry, University College London, London bSchool of Life and Medical Sciences, University of Hertfordshire, Hertfordshire, UK Received 11 April 2019 Accepted 13 August 2019 Supplemental Digital Content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's website, www.psychgenetics.com. Correspondence to Eirini Zartaloudi, MSc, UCL Division of Psychiatry, 6th Floor Maple House, 149 Tottenham Court Road, London W1T 7NF, UK, Tel: +44 20 7679 6562; e-mail: [email protected] Psychiatric Genetics: December 2019 - Volume 29 - Issue 6 - p 211-219 doi: 10.1097/YPG.0000000000000241 Buy SDC Metrics Abstract Endophenotypes are mediator traits between genetic influences and clinical phenotypes. Meta-analyses have consistently shown modest impairments of executive functioning in obsessive compulsive disorder (OCD) patients compared to healthy controls. Similar deficits have also been reported in unaffected relatives of OCD patients, but have not been quantified. We conducted the first meta-analysis combining all studies investigating executive functioning in unaffected relatives of individuals with OCD to quantify any deficits. A search of Pubmed, Medline and PsychInfo databases identified 21 suitable papers comprising 707 unaffected relatives of OCD patients and 842 healthy controls. Effect sizes were calculated using random effects models. Unaffected relatives displayed a significant impairment in global executive functioning. Analyses of specific executive functioning subdomains revealed impairments in: planning, visuospatial working memory and verbal fluency. Deficits in executive functioning are promising endophenotypes for OCD. To identify further biomarkers of disease risk/resilience in OCD, we suggest examining specific executive functioning domains. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.