Per- and polyfluoroalkyl substances (PFASs), commonly known as “forever chemicals”, are synthetic compounds with highly stable carbon–fluorine bonds, making them resistant to environmental degradation. These chemicals accumulate in ecosystems and water supplies, posing significant risks to human health, including cancer, immune system dysfunction, and neurological disorders. However, the mental health impacts of PFAS exposure remain underexplored, particularly in marginalized communities. This review examines the emerging evidence linking PFAS exposure to mental health issues such as anxiety, depression, and cognitive decline, with a focus on communities of color who face heightened vulnerability due to environmental and social health disparities. The review highlights the persistence of PFASs in the environment, common exposure pathways, and the disproportionate effects on populations living near contaminated sites. Despite some regulatory progress, U.S. regulations on PFASs are limited, especially compared to international standards. The review calls for stronger policy frameworks and emphasizes the need for environmental justice, health equity, and public awareness. By connecting environmental health, social justice, and mental well-being, the review aims to guide future research and policy reforms to mitigate the mental health consequences of PFAS exposure in vulnerable populations.

The oral microbiome, a highly diverse and intricate ecosystem of microorganisms, plays a pivotal role in the maintenance of systemic health. With the oral cavity housing over 700 different bacterial species, the body’s second most diverse microbial community, periodontal pathogens often lead to the dysregulation of immune responses and consequently, neuropsychiatric disorders. Emerging evidence suggests a significant link between the dysbiosis of oral taxa and the progression of neurogenic disorders such as depression, schizophrenia, bipolar disorders, and more. In this paper, we show the relationship between mental health conditions and shifts in the oral microbiome by highlighting inflammatory responses and neuroactive pathways. The connection between the central nervous system and the oral cavity highlights its role as a modulator of mental health. Clinically, these findings have significant importance as dysbiosis could compromise quality of life. The weight of mental health is often compounded with treatment resistance, non-adherence, and relapse, causing a further need for treatment development. This review seeks to underscore the crucial role of the proposed oral–brain axis in hopes of increasing its presence in future intervention strategies and mental health therapies.