The Effect of Oxcarbazepine in the Treatment of Agitation / Aggression in Dementia (OBAD)

Inclusion Criteria: * Alzheimer's dementia, vascular dementia or mixed forms of both according to ICD10 (F00, F01) criteria. * The patient is 55 years of age or older. * Residents at a nursing home and who have been there for at least 4 weeks prior to inclusion. * Signed informed consent by the patient or the relatives signed agreement that they have no reservations against patient's participation in the study. * At least one week history of agitation or aggression, score 6 or more in NPI-NH-subscale agitation/aggression. Exclusion Criteria: * Previous intolerability or known hypersensitivity to Oxcarbazepine or its equivalents * Low sodium serum levels \<135 mmol/L * Severe impaired renal function (creatinine clearance \<30 ml/min, calculated with Cockroft + Gault's formula) * Hepatic failure (transaminases (g-GT and ALAT \> 3 times upper normal limit). * Patients with AV-block II and III and all kinds of arrhythmia necessitating a treatment. * Severe somatic diseases that afford a change of medication and will compromise the attendance to the study. * Patients on cyclosporine. * Patients in need of strong analgesics like opioids as codeines * Patients taking carisoprodol * Alcohol or drug abuse during the last 12 months (used a higher dosage than prescribed) * The patient has been on ChEIs or memantine for less than 3 months or any change in the dosage during the last 2 weeks. * The patient is taking antiepileptics or antipsychotics (may be included two weeks after the use of antipsychotics has been ended). * The patient is taking MAOI or lithium * The patient with a dementia of type PDD, FTD or DLB * The patients with a severe or acute neurological disease (e.g. epilepsy, acute CVE, severe Parkinson's disease, acute confusion) or a severe psychiatric disorder like bipolar disorder, schizophrenia... * The patients who have participated in another clinical trial during the last 3 months. * The patients who have been randomized to the same study before.