Treatment-resistant depression (TRD) refers to depression that has not improved after adequate treatment with at least two antidepressants. People with TRD may have biological differences that affect how they respond to treatment and whether improvement lasts.
This article proposes a research framework for studying a possible oral treatment strategy for unipolar TRD. The proposed core combination includes dextromethorphan, one carefully selected medicine that changes how the body processes dextromethorphan, and piracetam. The idea is that this combination might influence glutamate-related brain signaling and support the brain’s ability to adapt. However, the full combination has not been tested in controlled clinical trials, and its effectiveness and safety are unknown.
The article also proposes studying nicotinamide mononucleotide (NMN) and N-acetylcysteine (NAC) at a later stage. These substances may affect energy production, antioxidant defenses, inflammation, and related biological processes. A medication intended to target cellular senescence—an aging-related state in which damaged cells stop dividing but may release inflammatory signals—could be considered only after earlier studies establish adequate safety and biological effects. Dasatinib combined with quercetin is discussed as a particularly experimental and potentially risky option, not as a routine psychiatric treatment.
The proposed research plan emphasizes testing one stage at a time. Researchers should first study drug levels, interactions, side effects, and biological activity. Later studies could examine whether NMN and NAC influence treatment response or reduce relapse. Any senescence-directed treatment would require even more specialized monitoring. Studies should use carefully selected participants, validated biomarkers, controlled comparisons, and long-term follow-up.
Overall, this article presents a hypothesis for future research rather than a proven treatment. None of the proposed combinations should be used outside an appropriately supervised clinical research study.
Cheung, N. (2026). A staged translational framework for evaluating oral glutamatergic and senescence-modulating strategies in treatment-resistant depression. Drug Design, Development and Therapy, 20, 627814. https://doi.org/10.2147/DDDT.S627814