Choroid Plexus: A Sensitive Structural Biomarker for Understanding Schizophrenia

The choroid plexus may play an important role in our understanding of schizophrenia as a multisystem disorder, serving as a sensitive structural biomarker for exploring the treatment and prevention of brain-periphery interaction abnormalities observed among individuals with the disease. A study on the subject was conducted among Han Chinese patients at the Beijing Huilongguan Hospital China, along with age- and sex-matched control individuals. Results of the analysis were published in the Schizophrenia Bulletin.

With the knowledge that schizophrenia is a brain disorder, the researchers sought to explore increasing evidence suggesting that bodywide involvement in the disease may exist as well. A total of 79 first-episode patients with schizophrenia within 2 weeks of initiation of antipsychotic medication were enrolled in the study, together with 41 age- and sex-matched healthy control individuals. Study recruitment occurred between 2017 and 2018.

To be included in the study, all patients needed to meet the schizophrenia criteria of the Structured Clinical Interview of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition; be between 16 and 45 years of age; have a total illness duration of <3 years and otherwise no prior exposure to antipsychotic medications; and be enrolled within 2 weeks of initiation of antipsychotic medication. All healthy volunteers were recruited from nearby communities and were excluded from the study if they had a history of psychiatric disorders or psychosis among first-degree relatives. At hospital admission, most of the patients had severe psychosis and were treated without any delay. The investigators examined group differences in subcortical brain regional structures, as measured by magnetic resonance imaging, along with subclinical cardiovascular, immune, neuroendocrine, and metabolic biomarkers, as indexed by allostatic load, and their possible associations with each other.

Study results showed that compared with healthy control individuals, patients with schizophrenia had significantly higher allostatic load (P =.001). Furthermore, lateral ventricle, choroid plexus, and thalamus volumes were all significantly larger among patients with schizophrenia (P <.001 for all), whereas amygdala volume was significantly smaller in patients with schizophrenia (P = .001).

The choroid plexus by itself was significantly associated with higher allostatic load, once age, sex, level of education, and total intracranial volume were taken into consideration (P <.001). In addition, higher allostatic load was significantly correlated with more positive symptoms (P =.016), but fewer negative symptoms (P =.008), according to findings from the Positive and Negative Syndrome Scale.

The investigators concluded that the peripheral multisystemic and central nervous system abnormalities observed among patients with schizophrenia may actually interact through the choroid plexus during the early stages of the disorder.

Reference

Zhou Y-F, Huang J-C, Zhang P, et al. Choroid plexus enlargement and allostatic load in schizophrenia [published online October 11, 2019]. Schizophr Bull. doi:10.1093/schbul/sbz100