Logotyp: till Uppsala universitets webbplats

Major depressive disorder (MDD) remains a leading cause of disability worldwide, with current treatments limited by delayed onset and low efficacy. The serotonergic psychedelic N,N-dimethyltryptamine (DMT) has shown rapid antidepressant effects in early clinical studies, yet its mechanisms and efficacy remain poorly characterized in established models of depression. Here, we evaluated the effects of a single dose of DMT (30 mg/kg, i.p.) in male mice exposed to the Chronic Unpredictable Mild Stress (UCMS) paradigm, a robust mouse model recapitulating key features of MDD, including anhedonia and cognitive impairment. DMT administered after UCMS reversed depressive-like behavior and restored cognitive performance, outperforming chronic fluoxetine across most domains. When administered during the stress period, DMT mitigated anhedonic responses but did not rescue cognitive deficits, suggesting a long-lasting domain-specific efficacy. Exploratory assessments in anesthetized animals showed that DMT's behavioral and cellular benefits persisted under isoflurane, though the role of the psychedelic experience remains uncertain due to potential confounding effects of isoflurane not controlled for in our design. Histological analyses revealed that all DMT regimes significantly increased adult-born granule cell (abGC) integration and reduced the number of ectopically abnormally integrated abGCs. Together, our findings highlight the robust and multifaceted effects of DMT on behavior and neurogenesis, positioning it as a promising candidate for rapid-acting antidepressant strategies that target structural circuit repair.