This issue of Psychiatric Clinics devoted to young onset dementia or early onset dementia presents information that is salient and valuable for clinical practice. The issue will update knowledge, present cultural and practical perspectives, examine priorities, and show opportunities for psychiatry practice and research in this group of dementias. Topics include: An epidemiologic perspective on young-onset dementias; The frontotemporal dementias; Posterior Cortical Atrophy: an atypical variant of Alzheimer disease; Rapidly progressive young-onset dementias: neuropsychiatric aspects; A guidance...