Symptoms

The symptoms depend on whether it is primarily the frontal or the temporal lobes that are affected. The parts of the frontal lobes that are affected are also a factor.

When the disease primarily affects the frontal lobes, it most often causes changes in the person's personality and social behaviour. That may manifest by the person becoming more apathetic and slow and they may become disinhibited. A person may develop more stereotypical behaviour where they are easily distracted. There are frequent mood swings and depression may occur

Incontinence of urine may occur early in the course.

Many of the symptoms observed in Alzheimer's disease do not develop until late (or at all) in frontotemporal dementia.