The Handbook of Mental Health and Aging, Third Edition provides a foundational background for practitioners and researchers to understand mental health care in older adults as presented by leading experts in the field. Wherever possible, chapters integrate research into clinical practice. The book opens with conceptual factors, such as the epidemiology of mental health disorders in aging and cultural factors that impact mental health. The book transitions into neurobiological-based topics such as biomarkers, age-related structural changes in the brain, and current models of accelerated aging in mental health. Clinical topics include dementia, neuropsychology, psychotherapy, psychopharmacology, mood disorders, anxiety, schizophrenia, sleep disorders, and substance abuse. The book closes with current and future trends in geriatric mental health, including the brain functional connectome, repetitive transcranial magnetic stimulation (rTMS), technology-based interventions, and treatment innovations.