Objectives:
The aim of the project was to assess the differences in the white matter (WM) fiber structure between patients with early onset schizophrenia (EOS), their first 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 Diffusion 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 significant differences in FA parameters were found between the analyzed groups. The group of patients took significantly 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 significant differences 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 and their first degree relatives compared to healthy subjects. The reported neuropsychological deficits were not reflected in WM integrity, as assessed with FA.