The study was fnanced with funds from the Polish Ministry of Science and Higher Education grant (project number: NN 402 465137). Evaluation of white matter structure changes, as assessed in tractography, and cognitive dysfunctions in patients with early onset schizophrenia and their frst-degree relatives Marta Gawłowska-Sawosz 1 , Agnieszka Pawełczyk 2 , Piotr Gębski 3 , Tomasz Pawełczyk 2 , Dominik Strzelecki 2 , Jolanta Rabe-Jabłońska 2 1 SYNAPSIS Foundation, Warsaw 2 Department of Afective and Psychotic Disorders, Medical University of Lodz 3 Medical Examination Centre, Medical University of Lodz Summary Aim. The aim of the project was to assess the diferences in the white matter (WM) fber structure between patients with early onset schizophrenia (EOS), their frst-degree relatives and controls using Fractional Anisotropy (FA), and an independent evaluation of the severity of working memory disturbances in the study groups. Methods. The study included 20 patients diagnosed with paranoid EOS (diagnosed before the age of 18), a group of 20 parents of patients, matched for gender, and 18 healthy controls. All study participants were examined with Difusion Tensor Imaging (DTI, 1.5 T) and selected neuropsychological tests to assess working memory, immediate memory and attention (Trail Making Test parts A and B: TMT-A and TMT-B, Digit Span Forward and Backward). Results. No signifcant diferences in FA parameters were found between the analyzed groups. The group of patients took signifcantly longer to perform the TMT-A and TMT-B than the control group, and achieved worse outcomes in Digit Span tests. The relatives of the patients achieved lower scores in Digit Span tests and needed more time to perform TMT-B compared to controls. There were no signifcant diferences between all groups in terms of the number of errors when performing TMT-A and TMT-B. Conclusions. The results of our study indicate a reduction in the capacity of immediate memory, working memory, cognitive plasticity and divided attention, both in EOS patients Psychiatr. Pol. 2017; 51(4): 735–750 PL ISSN 0033-2674 (PRINT), ISSN 2391-5854 (ONLINE) www.psychiatriapolska.pl DOI: http://dx.doi.org/10.12740/PP/OnlineFirst/67027