Comorbidity of depression and anxiety disorders : an evolutionary perspective

• Main Authors: Lek, Zhi Wei, Teo, Freda Juat Yi, Zhang, Xinyi
• Other Authors: Kitada Ryo
• Format: Final Year Project
• Language: English
• Published: 2018
• Subjects: DRNTU::Social sciences::Psychology::Deviant psychology
• Online Access: http://hdl.handle.net/10356/73830
• Institution: Nanyang Technological University

Depression and anxiety disorders are some of the most complex and prevalent mental disorders. The high comorbidity between these disorders has led to difficulties in diagnosis and treatment, resulting in worse outcomes for afflicted individuals. While the DSM-5 has proved useful as a diagnostic guide for depression and anxiety disorders, their comorbidity remains poorly understood. A new frame of enquiry may lie in the evolutionary perspective, which examines mental disorders in the context of adaptations and functions. Given how few studies have applied the evolutionary perspective specifically to the issue of comorbidity, we examined depression and anxiety disorders with regards to their similarities and differences across Tinbergen’s (1963) four questions of ethology which comprise of mechanism, ontogeny, function, and phylogeny. Overall, depression and anxiety disorders share large similarities in the aspect of mechanism, but share a mixture of similarities and differences across the aspects of ontogeny, function and phylogeny. The evolutionary perspective is also discussed with regards to its possible contributions and insights for diagnosis and treatment. By examining depression and anxiety disorders in an evolutionary framework, this paper aims to explore how their origins and functions can contribute to a more holistic understanding of these disorders.