Schneiderian first rank symptoms in schizophrenia: A developmental neuroscience evaluation

• Schizophrenia patients with, and without first rank symptoms (FRS) compared with controls.
• Dense array (256 sensor) EEG Gamma power, serum BDNF levels and ‘self monitoring’ assessed.
• Increased gamma power in right hemispheric regions in patients with FRS found.
• Lower BDNF and ‘self monitoring’ in patients with FRS found.
• Schizophrenia patients with FRS hypothesized as a distinct developmental sub group.

IntroductionSelf disorders in schizophrenia have been suggested to have distinct neurobiological underpinnings. Using comprehensive neuro-scientific assessments including a neurophysiological, a neurochemical and a neuropsychological marker, this study assesses disordered-“self” in schizophrenia.MethodsTwenty schizophrenia patients with first rank symptoms (FRS;FRS+), 20 patients without FRS (FRS−) and 20 healthy controls (HC) were assessed for psychopathology, especially on specially designed FRS score sheets with a narrow and a broad definition. Resting state electroencephalography was acquired using 256-electrodes; gamma spectral-power was measured in 8 regions of interest. Serum BDNF and self-monitoring were also assessed. Comparative and correlation analysis were conducted in addition to a step-wise discriminant function analysis.ResultsFRS+ group with greater positive symptom score and a lower negative symptom score, showed significantly increased gamma spectral power, especially on right hemispheric regions, along with lower BDNF levels and lower scores on self-monitoring compared to FRS− and HC. Serum BDNF levels and gamma spectral power in the region corresponding right inferior parietal lobule were identified as predictors that most accurately classified the defined groups.ConclusionsSchizophrenia patients satisfying the criteria of presence of first rank symptoms represent a distinct neurodevelopmental subgroup with associated features of predominantly positive symptoms, significantly lower neurotrophin levels, aberrant resting state brain activity in the heteromodal association cortex and performing poorer on self-monitoring tasks.