The neuroinflammation hypothesis holds that elevation of cytokines and reactive oxygen species in the brain mediates the deleterious effects of urban air pollution on the central nervous system (CNS). Studies in human and animal research document that neuroinflammation occurs in response to several inhaled pollutants. Microglia are a prominent source of cytokines and reactive oxygen species in the brain, implicated in the progressive neuron damage in diverse neurodegenerative diseases, and activated by inhaled components of urban air pollution through both direct and indirect pathways. The MAC1-NOX2 pathway has been identified as a mechanism through which microglia respond to different forms of air pollution, suggesting a potential common deleterious pathway. Multiple direct and indirect pathways in response to air pollution exposure likely interact in concert to exert CNS effects.

Pharmacotherapy and psychotherapy effectively treat major depression among primary care patients when provided within specific parameters and for the full acute and continuation phases. Treatment principles recommended by the Depression Guideline Panel of the Agency for Health Care Policy and Research are supported.

Although Alzheimer's disease is widely regarded as a leading cause of death, dementias are reported on the death certificates of only a quarter of demented individuals in the population at large. Reporting is more likely in those with more advanced dementia, with Probable Alzheimer's disease, and those who die in long-term care institutions.

Physicians noted impairment in a minority of impaired patients. They tested mental status in those with documented cognitive and functional difficulties, in very mildly impaired patients, and in those for whom they intervened.