1. Treatment Resistant Depression overview in Adult Cheng-Ta Li 2. Treatment Resistant Depression in Children and Adolescents Susan Shur-Fen Gau, Jung-Chi Chang and Hai-Ti Lin 3. Treatment Resistant Depression in Elderly Mu-N Liu 4. Headache and Treatment Resistant Depression Shih-Pin Chen 5. Insomnia and Treatment Resistant Depression Wei-Chen Lin and John Winkelman 6. Tinnitus and Treatment Resistant Depression Lieber Po-Hung Li and Berthold Langguth 7. Genetics of Antidepressant Response and Treatment Resistant Depression Yen-Feng Lin 8. Neuroinflammation via Gut-Microbiota-Brain Axis in Treatment Resistant Depression Kenji Hashimoto 9. Molecular Imaging findings for Treatment Resistant Depression Kai-Chung Yang 10. Functional MRI markers for Treatment Resistant Depression: Insights and Current Challenges Vasileia Kotoula, Carlos A. Zarate Jr. and Jennifer W. Evans 11. Medication Strategies for Treatment Resistant Depression Siegfried Kasper 12. Brain Stimulation for Treatment Resistant Depression André R. Brunoni, Laís Razza, Aluísio Rodrigues and Lisiane Martins 13. Electroconvulsive Therapy for Treatment Resistant Depression Ming-Hsien Hsieh 14. Next Generation Antidepressants with Novel Mechanisms for Treatment Resistant Depression Mu-Hong Chen 15. Psychological aspects and Psychotherapy for Treatment Resistant Depression Li-Yu Hu 16. Psychiatric Rehabilitation for Treatment Resistant Depression Chih-Ming Cheng