The goal of this observational study is to learn about social cognition and risky behaviour in patients with young-onset dementia (YOD). The investigators want to

• Examine differences in performance on social cognition test and measures of risky behaviour between behavioural variant YOD patients, patients with frontal brain injury, non-behavioural YOD patients and healthy controls.
• Examine if there is a relation between social cognition tests and measures of risky behaviour.

Participants will be administered a neuropsychological assessment including social cognition measures and patients will complete a driving simulator task in which risky behaviour will be elicited.

Inclusion Criteria:

All subjects

• Sufficient command of the Dutch language
• In possession of a driver's license with any driving experience throughout life
• Age 18 to 65

bvYOD subjects

• Probable diagnosis of young-onset dementia (before 65 years old), confirmed after interdisciplinary consensus meeting in which interviews, neuropsychological examination, neurological and psychiatric assessments, neuro-imaging, blood samples, and in some cases FDG/PIB-PETscans, CSF biomarkers or genetic counseling were discussed.
• Nosological diagnosis of bvFTD or bvAD

Non-bvYOD subjects

• Probable diagnosis of young-onset dementia (before 65 years old), confirmed after interdisciplinary consensus meeting in which interviews, neuropsychological examination, neurological and psychiatric assessments, neuro-imaging, blood samples, and in some cases FDG/PIB-PETscans, CSF biomarkers or genetic counseling were discussed.
• YOD subtypes other dan bvFTD or bvAD, such as amnestic variant AD.

Frontal brain injury subjects

- Neurological patients with frontal brain injury (e.g. traumatic brain injury, stroke or brain tumor patients).

Exclusion Criteria:

All subjects

• Suffering from severe motion sickness; motion sickness is a risk factor for simulator sickness

YOD subjects:

- Presence of premorbid severe neurological or psychiatric pathology, non-related to dementia.

Frontal brain injury subjects:

- Presence of serious psychiatric disorders or other neurological comorbidities.

Healthy control subjects:

• Presence of serious psychiatric disorders
• History of neurological disorders, which may interfere with cognitive functioning (e.g. recent concussion, previous subarachnoid or intracerebral haemorrhage, intracranial tumours, epilepsy, ischemic stroke).

Patients with young-onset dementia, i.e. onset of dementia before the age of 65 years.