GLP-1 Receptor Agonists for Non-obese Asian Patients With Schizophrenia: Beyond the Body Mass Index Paradigm

See related commentary by McIntyre

To the Editor: I read with great interest the commentary by Dr McIntyre¹ on prescribing glucagon-like peptide-1 receptor agonists (GLP-1 RAs) for persons with mental disorders. The author elegantly dichotomized clinical targets into evidence-based and aspirational categories, highlighting the utility of GLP-1 RAs in mitigating weight gain and metabolic disruption associated with psychotropic drugs like clozapine. However, to optimize the clinical deployment of GLP-1 RAs in global psychiatry, we must expand our focus beyond the classical obesity-centered paradigm and consider critical ethnic variations in metabolic pathophysiology, particularly among Asian populations.

Antipsychotic-induced metabolic dysregulation in Asian patients with schizophrenia frequently manifests without a substantial increase in body mass index.² To explain this phenomenon, we recently proposed a “two-speed” model of pancreatic β-cell failure.³ The acute pathway involves direct chemical/proteotoxic stress in the endoplasmic reticulum caused by specific second-generation antipsychotics—most notably clozapine and olanzapine—leading to proinsulin misfolding, secretory pathway blockage, and rapid-onset hyperglycemia, independent of peripheral adiposity. The chronic pathway involves transcriptional shutdown and β-cell dedifferentiation under sustained metabolic demand. This β-cell-centric perspective introduces unique implications for GLP-1 RAs. Beyond weight loss, GLP-1 RAs facilitate glucose-stimulated insulin secretion and exert prominent cytoprotective, antiapoptotic, and autophagy-stimulating effects.⁴ Since the autophagy-lysosome system is essential for clearing the misfolded proinsulin aggregates induced by clozapine,³ GLP-1 RAs may provide direct rescue benefits to vulnerable β-cells in non-obese patients, representing a mechanism-based intervention rather than a mere weight-management tool.

Regarding the “aspirational” targets for core psychopathology, the neurobiological overlap between incretin signaling and schizophrenia pathophysiology warrants a nuanced examination. Central GLP-1 receptors are widely expressed in brain regions subserving reward, learning, and cognition.⁵ Accumulating evidence indicates that GLP-1 signaling enhances neuronal plasticity and mitigates neuroinflammation, which could theoretically ameliorate cognitive and affective deficits in schizophrenia. Nevertheless, whether these central actions can effectively overcome the profound neurochemical anomalies seen in treatment-resistant schizophrenia remains a high hurdle. Severe clozapine-resistant schizophrenia (CRS) is increasingly anchored in N-methyl-D-aspartate receptor (NMDAR) hypofunction on cortical GABAergic interneurons, leading to a disinhibition model and chaotic glutamate release.⁶ While GLP-1 RAs modulate synaptic transmission, they may lack the specific, high-affinity capacity required to restore homeostatic glutamatergic signaling at the NMDAR complex. Breakthroughs in CRS management may still necessitate direct glutamatergic modulators with fast off-rate kinetics, such as dextromethorphan, rather than peripheral-central incretin pathways.⁷

In conclusion, viewing diabetes in schizophrenia as a heterogeneous condition driven by β-cell vulnerability underscores the need for proactive metabolic strategies in non-obese Asian populations. Clarifying whether GLP-1 RAs can rescue acute proteotoxic β-cell stress from clozapine, while delineating their synaptic boundaries in glutamatergic networks, represents a vital research priority to optimize integrated care and reduce excess mortality.

Article Information

Published Online: July 6, 2026. https://doi.org/10.4088/JCP.26lr16549
© 2026 Physicians Postgraduate Press, Inc.
J Clin Psychiatry 2026;87(3):26lr16549
To Cite: Nagamine T. GLP-1 receptor agonists for non-obese Asian patients with schizophrenia: beyond the body mass index paradigm. J Clin Psychiatry 2026;87(3):26lr16549.
Author Affiliation: Sunlight Brain Research Center, Hofu, Yamaguchi, Japan.
Corresponding Author: Takahiko Nagamine, MD, PhD, Sunlight Brain Research Center, 4-13-18 Jiyugaoka, Hofu, Yamaguchi, 747-0066, Japan ([email protected]).
Financial Disclosure: None.
Funding/Support: None.
ORCID: Takahiko Nagamine: https://orcid.org/0000-0002-0690-6271