Dementia in young adults is not very well studied in terms of clinical effects on the patient, and not much is known about the effects on spouses and caregivers. This study assessed the psychological impact of the diagnosis of young onset dementia on spouses. A questionnaire that used the Zarit Burden Interview and the Beck Depression Index was sent to 120 spouses of a cohort of patients with established diagnoses of young onset dementia (age of onset before 65 years), including frontotemporal lobar degeneration, Alzheimer's disease, and primary progressive aphasia. A total of 100 usable responses were received. The mean age of respondents was 62.3 years (54% women, 46% men). A cross-sectional analysis showed that the diagnosis of young onset dementia has a significant impact on spouses, characterized by concerns of dependency, fear, and increased depression, especially in the spouses of patients with frontotemporal lobar degeneration.