Trace elements in schizophrenia: a systematic review and meta-analysis of 39 studies (N = 5151 participants)

Abstract

Context The pathogenesis of schizophrenia appears to be multifaceted. Objective The aim of this meta-analysis of studies that investigated blood and hair concentrations of trace elements in people diagnosed with schizophrenia was to determine whether levels of trace elements in patients with schizophrenia differ from those in healthy individuals. Data Sources The PubMed, Scopus, and Web of Science databases were searched to January 2018. Study Selection Studies that compared concentrations of trace elements in patients with schizophrenia with those in healthy controls, in patients with schizophrenia under different treatment regimens, or in patients with schizophrenia at different stages of disease were included. Data Extraction Data on study and sample characteristics and measures of trace elements were extracted. Results Thirty-nine studies with a total of 5151 participants were included. Meta-analysis of combined plasma and serum data showed higher levels of copper, lower levels of iron, and lower levels of zinc among patients with schizophrenia vs controls without schizophrenia. Subgroup analyses confirmed the following: higher levels of copper in plasma, in users of typical antipsychotic drugs, and in males; lower levels of zinc in serum, in patients in Asia, in drug-naive/drug-free patients, and in inpatients; lower levels of iron in serum, in patients in Asia, in drug-naive/drug-free patients, in patients on antipsychotic drugs, in inpatients, in patients with acute or newly diagnosed schizophrenia, in patients with chronic or previously diagnosed schizophrenia, and in males; and lower levels of manganese in plasma and in patients with chronic or previously diagnosed schizophrenia. Conclusions This meta-analysis provides evidence of an excess of copper, along with deficiencies of zinc, iron, and manganese, in patients with schizophrenia.

The Role of Selenium in Pathologies: An Updated Review

“…On the other hand, a 2020 review and meta-analysis of 10 studies with a total of 1784 participants compared blood selenium levels in patients with schizophrenia and healthy controls. The results showed no significant association between schizophrenia and blood selenium levels [ 301 ].…”

Lowered serum cesium levels in schizophrenia: association with immune-inflammatory biomarkers and cognitive impairments

“…5,6 Some investigators have recently reported that SCZ is accompanied by changes in trace/metal elements, although contradictory results were obtained with different types of metals, SCZ, and methods. [11][12][13][14][15] Importantly, Cai et al 15 found a significant reduction in serum levels of the alkali metal cesium in individuals with SCZ in comparison with healthy controls. This may be important because cesium shares some similarities with potassium, and therefore may interfere with potassium metabolism, 16 while a single nucleotide polymorphism (SNP) in the KCNH2 gene, which encodes the pore-forming subunit of potassium channels, has been associated with SCZ and with cognitive impairments.…”

Is there any association between manganese level and schizophrenia? - a descriptive review

“…Toxic amount of Mn called manganism can also manifest itself by early psychotic symptoms [11]. Rats developed schizophrenialike behaviors after large administration of manganese chloride [12]. This is caused by the ability of Mn to produce free radicals and then, consequently, contribute to neurodegeneration [13].…”

“…NO can cause free radical-mediated neurotoxicity and can be found in high concentrations in patients with schizophrenia [20,21]. Consequently, researchers try to estimate to what extent manganese playsa role in the arginine-NO pathway and if it can be used in treatment [12].…”