Objectives: Inflammation, measured by abnormal blood C-reactive protein (CRP) level, has been described in schizophrenia (SZ), being inconsistently related to impaired cognitive functions. The aim of the present study is to investigate cognitive impairment associated with abnormal CRP levels in a large multi-centric sample of community-dwelling SZ patients, using a comprehensive neuropsychological battery. Method: Three hundred sixty-nine community-dwelling stable SZ subjects (76.2% men, mean age 32.7 y) were included and tested with a comprehensive battery of neuropsychological tests. Abnormal CRP level was defined as >3mg/L. Results: Multiple factor analysis revealed that abnormal CRP levels, found in 104 patients (28.2%), were associated with impaired General Intellectual Ability and Abstract Reasoning (aOR = 0.56, 95% CI 0.35–0.90, P = .014), independently of age, sex, education level, psychotic symptomatology, treatments, and addiction comorbidities. Abnormal CRP levels were also associated with the decline of all components of working memory (respectively effect size [ES] = 0.25, P = .033; ES = 0.27, P = .04; ES = 0.33, P = .006; and ES = 0.38, P = .004) and a wide range of other impaired cognitive functions, including memory (ES = 0.26, P = .026), learning abilities (ES = 0.28, P = .035), semantic memory (ES = 0.26, P = .026), mental flexibility (ES = 0.26, P = .044), visual attention (ES = 0.23, P = .004) and speed of processing (ES = 0.23, P = .043). Conclusion: Our results suggest that abnormal CRP level is associated with cognitive impairment in SZ. Evaluating the effectiveness of neuroprotective anti-inflammatory strategies is needed in order to prevent cognitive impairment in SZ.

Objective: To compare the clinical symptomatology in patients with Early‐Onset Schizophrenia (EOS, N = 176), especially the subgroup Very Early Onset Schizophrenia (VEOS) and Adult Onset Schizophrenia (AOS, N = 551).Method: In a large French multicentric sample, 727 stable schizophrenia patients, classified by age at onset of the disorder, were assessed using standardized and extensive clinical and neuropsychological batteries: AOS with onset ≥ 18 years and EOS with onset < 18 years (including 22 VEOS < 13 years).Results: The importance of better diagnosing EOS group, and in particularly VEOS, appeared in a longer DUP Duration of Untreated Psychosis (respectively, 2.6 years ± 4.1 and 8.1 years ± 5.7 vs. 1.0 years ± 2.5), more severe symptomatology (PANSS Positive And Negative Syndrome Scale scores), and lower educational level than the AOS group. In addition, the VEOS subgroup had a more frequent childhood history of learning disabilities and lower prevalence of right‐handedness quotient than the AOS.Conclusion: The study demonstrates the existence of an increased gradient of clinical severity from AOS to VEOS. In order to improve the prognosis of the early forms of schizophrenia and to reduce the DUP, clinicians need to pay attention to the prodromal manifestations of the disease.