Cognitive impairments in first-episode psychosis patients with attenuated niacin response.

Background: Psychosis is a complex brain disorder with diverse biological subtypes influenced by various pathogenic mechanisms, which can affect treatment efficacy. The ANR(Attenuated Niacin Response) subtype is characterized by pronounced negative symptoms and functional impairments, suggesting a distinct clinical profile. However, research on the cognitive characteristics associated with the ANR subtype in drug-naïve first-episode psychosis(FEP) patients remains limited.

Methods: This observational study involved 54 FEP patients and 52 healthy controls(HC). Clinical psychopathology was assessed using the Positive and Negative Syndrome Scale(PANSS), while cognitive performance was evaluated through the Chinese version of the MATRICS Consensus Cognitive Battery(MCCB). Additionally, niacin response was measured using aqueous methylnicotinate patches, with responses quantified to classify participants into ANR or normal niacin response (NNR) groups.

Results: Among the FEP patients, 25.9 % were classified as having ANR, significantly higher than the 7.7 % in the HC group (  = 6.247,  = 0.012). The ANR group exhibited more severe negative symptoms and higher total PANSS scores compared to the NNR group, with significant differences in cognitive performance on the Trail Making test and the Brief Visuospatial Memory Test-Revised. Correlation analyses revealed a significant positive relationship between overall symptom severity and niacin response, as well as between cognitive performance and niacin response, particularly for the Trail Making and Symbol coding tests.

Conclusions: This study demonstrates that the ANR subtype in first-episode psychosis is linked to more severe negative symptoms and cognitive impairments. Targeted assessments and interventions for patients with ANR may improve treatment outcomes and enhance understanding of cognitive dysfunction in psychotic disorders.