Inflammation Associated With Cognitive Decline in Patients With Schizophrenia

Inflammation may be linked to cognitive decline in patients with schizophrenia, leading study authors to encourage a better understanding of underlying pathways to improve outcomes for this patient population. The findings were published in Progress in Neuro-Psychopharmacology and Biological Psychiatry.

“Schizophrenia is a complex psychiatric disorder that includes positive and negative symptoms but also debilitating cognitive deficits. Current pharmacological interventions do not target these deficits,” wrote a research team from Ireland.

Seeking to address research gaps, investigators analyzed data from 25 studies to better understand the association between cognitive performance and the inflammatory markers Interleukin-6 (IL-6), IL-1β, Tumor Necrosis Factor-α (TNF-α), and C-reactive protein (CRP). The meta-analysis used PubMed and Web of Science databases and included 2398 patients.

There was a significant inverse relationship between systemic plasma levels of all 4 inflammatory markers and several measures of cognitive performance, including attention-processing speed, executive function, working memory, verbal and visual learning, and verbal and visual memory.

The significant decline in cognitive performance was associated with the following ranges for each biomarker:

• -0.136 to -0.181 for IL-6;
• -0.372 to -0.476 for IL-1β;
• -0.188 to -0.38 for TNF-α; and
• -0.168 to -0.311 for CRP.

Researchers concluded the findings suggest a relationship between inflammation and cognitive decline in patients with schizophrenia, with cognitive deficits reflecting elevated levels of proinflammatory biomarkers.

“Understanding the underlying pathways between them could have a significant impact on the disease progression and quality of life,” they said.

Reference:
Patlola SR, Donohoe G, McKernan DP. The relationship between inflammatory biomarkers and cognitive dysfunction in patients with schizophrenia: A systematic review and meta-analysis. Prog Neuropsychopharmacol Biol Psychiatry. Published online October 22, 2022. doi:10.1016/j.pnpbp.2022.110668