Methods for modulating macrophage proliferation in an individual afflicted with or at risk for a macrophage-associated disease are provided. The methods employ a polyamine analog, or salt or protected derivative thereof. Macrophage proliferation has been implicated in a number of serious disorders, including AIDS (HIV)-associated dementia, AIDS-associated non-Hodgkin's lymphoma, and Alzheimer's disease. The invention also provides methods for aiding diagnosis and monitoring therapy of a macrophage-associated non-HIV associated dementia, especially Alzheimer's disease. The invention also provides methods of delaying development of macrophage-associated non-HIV associated dementias, including Alzheimer's disease, which entail administration of an agent which modulates macrophage proliferation.