# From metabolism to mood regulation: astrocytes as a driver of depression

## TL;DR

This paper explores how astrocytes, brain cells once thought to only support neurons, may play a key role in depression through their metabolic functions.

## Contribution

The paper systematically reviews experimental evidence showing how manipulating astrocyte function can directly influence depression-like behaviors.

## Key findings

- Reduced astrocyte density and impaired glutamate–glutamine cycling are linked to depressive-like behaviors.
- Enhancing astrocytic functions rescues stress-induced depression phenotypes in experimental models.
- Astrocyte alterations are connected to circuit-level dysfunctions like impaired prefrontal–amygdala regulation.

## Abstract

Astrocytes are increasingly recognized as active regulators of mood and cognition, extending far beyond their classical supportive roles. In major depressive disorder, converging evidence from postmortem analyses, magnetic resonance spectroscopy (MRS), and animal stress models points toward the possibility of astrocytic abnormalities, including reduced density, impaired glutamate–glutamine cycling, and altered mitochondrial function. However, the causal contribution of these alterations remains insufficiently defined. This review aims to summarize experimental studies employing both loss- and gain-of-function approaches to directly probe the involvement of astrocytes in depression. We first introduce which inhibited astrocytic functions induce depressive-like behaviors, and then explore how enhancing these astrocytic functions—through overexpression and pharmacological manipulation methods—rescues stress-induced depression phenotypes. We further connect astrocyte alterations with circuit-level dysfunctions and behavioral outcomes, such as impaired prefrontal–amygdala regulation and reduced mesolimbic reward responses. Finally, we discuss therapeutic opportunities including astrocyte-targeting pharmacological strategies and MRS-based biomarkers. By integrating mechanistic evidence with translational perspectives, this review positions astrocyte metabolism as a promising frontier for antidepressant development.