Inclusion Criteria:

• Frontotemporal dementia meeting diagnostic criteria of the Report of the Work Group on Frontotemporal Dementia and Pick's Disease (McKhann et al, 2001). Diagnosis will be established by clinical interview by a geriatric psychiatrist or neuropsychiatrist, experienced with the diagnosis of FTD. Patients with the language presentation of FTD will be enrolled if their behavioral disturbance meets the inclusion criteria. Use of these diagnostic criteria would allow for enrollment of patients who in a clinical setting carry the diagnosis of: semantic dementia, primary progressive aphasia, cortical-basal degeneration, progressive supranuclear palsy, (amyotrophic lateral sclerosis (ALS) with dementia, and Pick's disease, as all of these diagnoses are now classified under the rubric of FTD.
• Frontal Behavioral Inventory (FBI) disinhibition subscale score of >16 (Kertesz et al,1997; Kertesz et al 2000). Explanation of this subscale is found under outcome measures.
• Men, women and minority groups will be included, ages 40-90 years old.
• Judged by the attending psychiatrist to be in sufficiently good health so as to be treated using the study protocol in usual outpatient care circumstances.
• Patient, caregivers and or legal representatives provide informed consent for participation in the study, using standard Johns Hopkins Division of Geriatric Psychiatry and Neuropsychiatry procedures.
• Caregiver is available who spends at least 10 hours per week with the patient and is able and willing to accompany the patient in the course of the study and to provide collateral information.

Exclusion Criteria:

• Presence of a brain disease that might otherwise fully explain the presence of dementia or behavior disturbance, such as stroke, Parkinson's disease, traumatic brain injury, multiple sclerosis, and the like.
• Treatment with amantadine is contraindicated in the opinion of the study attending psychiatrist. Examples of this would be patients with advanced heart, liver or kidney disease or a seizure disorder. Creatinine clearance >50mL/min will be required, calculated using the Cockcroft-Gault equation.
• Failure of treatment with amantadine for behavior disturbance of FTD in the past.
• Treatment with a medication that would prohibit the safe concurrent use of amantadine.
• Ongoing regular alcohol use and an unwillingness to stop drinking alcohol during the study period.
• Pregnancy or lactation.