# Differentiation of psychotic and affective disorder patients from healthy controls using the niacin skin flush test: a novel analytical method and the SKINREMS system—preliminary research

## TL;DR

A new method using the niacin skin flush test helps distinguish people with psychotic and affective disorders from healthy individuals, offering a potential tool for diagnosis.

## Contribution

A novel analytical method and the SKINREMS system were developed to standardize and improve the niacin skin flush test for psychiatric diagnosis.

## Key findings

- The NSFT differentiated patients from healthy controls based on color saturation and time points.
- The test showed potential to distinguish between subgroups of patients with different disorders.
- The NSFT is a fast, effective, and low-cost method for identifying individuals with psychotic disorders.

## Abstract

According to the phospholipid membrane theory of psychotic disorders, fatty acid metabolism may play a role in the etiopathogenesis of schizophrenia (SCH) and related disorders. Weakened skin reactions to niacin have been documented in SCH and bipolar disorder (BD), prompting research into biomarkers underlying these responses. So far, there is also no standard for performing and interpreting the niacin skin flush test (NSFT) which creates an opportunity for development in this area. The NSFT was conducted based on the SKINREMS system and an original method of analyzing measurements. 120 individuals including 33 patients diagnosed with first-episode psychosis (FEP), 22 with BD, 13 with schizoaffective disorder (SA), 13 with chronic schizophrenia (CS), and 39 healthy controls (HC) participated in the study. NSFT differentiated patients from HC and among subgroups of patients based on color saturation, specific time points, and niacin solution concentrations. The NSFT is a fast, effective, and cheap method that allows the differentiation of individuals suffering from psychotic disorders from HC. Standardization of the test method may contribute to more precise searches for biomarkers responsible of responses in the NSFT and can support the diagnostic process. The presented study is preliminary and exploratory in nature. Developing a method of using NSFT may contribute to a more precise search for biomarkers responsible for the results and thus to the diagnostic process.