Evidence for cytokine dysregulation in schizophrenia spectrum disorders: A comparison of cerebrospinal fluid and blood samples

Abnormalities in immune function have been described in schizophrenia but few studies have investigated cytokines in cerebrospinal fluid (CSF) and their correlation with blood levels. In this cross-sectional study, cytokines were measured in CSF and plasma of 30 subjects with schizophrenia spectrum disorder (SSD) diagnosis and 23 healthy volunteers (HV). Results showed that CSF TNFα was increased in SSD subjects compared to HV and there were no correlations between CSF and plasma cytokine levels. The present findings provide evidence of dysregulation of TNFα in CSF of schizophrenia. These results identify elevated CSF TNFα levels as a potential biomarker in schizophrenia.

Cognition and daily life functioning among persons with serious mental illness: A cluster analytic examination of heterogeneity on the Test of Grocery Shopping Skills

OBJECTIVE

To characterize variability in daily life functioning among individuals with serious mental illness based on a naturalistic performance measure of grocery shopping and standard neuropsychological tasks using cluster analytic methods.

METHODS

A naturalistic performance measure, the Test of Grocery Shopping Skills (TOGSS), and standard neuropsychological tasks, were completed by 191 participants with serious mental illness. Hierarchical cluster analytic techniques were used to explore functional subgroups based on naturalistic performance measure variables. Multivariate analyses of variance were utilized to compare subgroups on TOGSS variables and neuropsychological measures, respectively.

RESULTS

Two distinct functional subgroups emerged from the cluster analysis. On average, participants in cluster one were faster, more efficient, and more accurate compared to cluster two. Based on performance on neuropsychological tasks, cluster one had better verbal memory, visual attention, and processing speed, and executive functioning scores, compared to cluster two. The clusters did not differ on a measure of auditory working memory.

CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

Naturalistic performance measures can assist with characterizing the heterogeneity in real life functioning among people with serious mental illness. Further work to illuminate the relationship between specific cognitive abilities and specific functional abilities is warranted and may assist with targeting effective treatment plans for functional recovery. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Cytokines in cerebrospinal fluid of patients with schizophrenia spectrum disorders: New data and an updated meta-analysis

Few studies have been conducted examining cytokines in cerebrospinal fluid of patients compared to healthy volunteers. The goals of this study were: 1) to report original data detailing cytokine levels in the cerebrospinal fluid (CSF) of 10 patients with a schizophrenia spectrum disorder (SSD) diagnosis and 10 healthy controls and 2) to conduct a meta-analysis of the available data on cytokine levels in the CSF of patients with SSD compared to healthy controls, including our new data. Cytokine concentrations were measured using the Q-plex Human Cytokine Screen array in CSF of 10 patients with SSD and 10 healthy volunteers. For the meta-analysis, an electronic PubMed and Google Scholar search without restrictions was conducted for articles that reported on cytokine levels in CSF in patients with an SSD compared to healthy controls. Our original data revealed statistically significant increases in levels of interleukin-8 (IL-8) and interleukin-1 beta (IL-1β) in the CSF of patients with an SSD compared to healthy volunteers. Our meta-analysis showed statistically significant increases in interleukin-6 (IL-6) and IL-8 in patients compared to healthy volunteers. Effect sizes between treated and untreated patients for IL-6 were of similar magnitude. However, IL-6 levels were higher in early stage schizophrenia patients compared to chronic schizophrenia patients. Studies with larger sample sizes, comprehensive assessments and ideally in the context of a randomized controlled intervention to minimize the impact of confounding factors are needed to fully understand the role of cytokines and inflammatory markers in the pathophysiology and treatment of schizophrenia.