*2.1. Study Participants*

The age of eligible participants ranged between 18 and 65. Forty outpatients suffering from schizophrenia (SZ group) according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria [14] were recruited in the study. Out of them, 95% were treated with antipsychotic medication. Forty healthy volunteers matched for age and body mass index (BMI) were enrolled in the study, as the control (HC group). Participants from the HC group had no psychiatric, inflammatory-related, metabolic disorders, or other health problems which in the examiner's opinion could have affected FA metabolism, while they were also not taking any medication. Neither group followed any specific diet within the six months prior to the examination. Before entering the study, all subjects gave their informed consent to participate. The study was conducted in accordance with the Declaration of Helsinki [15], and the protocol was approved by the Ethics Committee of Medical University of Lublin, Poland (Project identification code: KE-0254/127/2016, 28 April 2016).
