Alterations in the inflammatory and immune systems have been documented to occur from the earliest stages of
schizophrenia, and have been associated with neurodevelopmental changes.
Cognitive impairment is a core feature in the pathology of
schizophrenia, and recent studies showed a significant increase in serum
IL-18 in
schizophrenia, and a putative role of
IL-18 in neuroprogression and thus neurocognitive defects. The purpose of this study was to examine the association of
IL-18 with cognitive deficits in
schizophrenia. We recruited 77 first episode and
drug naïve schizophrenic patients and 75 healthy control subjects and examined the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and serum
IL-18 in both groups. Schizophrenic symptoms were assessed using the positive and negative syndrome scale (PANSS). We found that
IL-18 levels were non-significantly higher in patients than controls (206.0±92.9 pg/ml vs 193.2±41.8 pg/ml, p=0.28). Cognitive scores on the RBANS and nearly all of its five subscales (all p<0.05) except for the Visuospatial/Constructional index (p>0.05) were significantly lower in schizophrenic patients than normal controls. For the patients,
IL-18 was positively associated with the Visuospatial/Constructional domain of cognitive deficits in
schizophrenia. Our findings suggest that cognitive deficits occur during the acute stage of a schizophrenic episode, and
IL-18 may be involved in Visuospatial/Constructional deficits of these patients.