Frontotemporal dementia (FTD) is the most common type of dementia in people under 60. The disorder occurs in the frontal and temporal lobes of the brain—the areas behind the forehead and behind the ears which control speech and personality. Also known as frontal lobe dementia or frontotemporal lobar degeneration (FTLD), frontotemporal dementia eventually leads to changes in character and behavioras well as impairment in intellect, memory, and speech. FTD also tends to occur at an earlier age than Alzheimer’s disease, usually first appearing in adults between the ages of 40 and 60 and progressing over time.