Treatment-Resistant Depression, Part B, Volume 281 in the Progress in Brain Research series, highlights new advances in the field, with this new volume presenting interesting chapters on highly relevant topics such as Treatment Resistant Depression in Children and Adolescents, Treatment Resistant Depression in Elderly, Brain Stimulation for Treatment Resistant Depression, Electroconvulsive Therapy for Treatment Resistant Depression, Psychological aspects and Psychotherapy for Treatment Resistant Depression, Psychiatric Rehabilitation and Cognitive Deficit for Treatment-Resistant Depression, Insomnia and Treatment Resistant Depression, and Tinnitus and Treatment Resistant Depression.