Depression and anxiety are illnesses of modernity and valuable adaptations of the past. Reviewing the evolutionary theories allows us to understand the adaptive advantages of the symptoms of depression and anxiety and how it benefits survival and evolutionary fitness.
Thus, an evolutionary perspective proposes that psychiatry should consider disorders and disabilities in new ways. Natural selection has shaped the complexity of the human brain, including normal functioning and the possibility for dysfunctions, during evolutionary time. Reviewing the adaptive advantages of these disorders does not imply that they are necessary and useful in our modern environments. Depression still is one of the leading causes of deaths; 700,000 people die annually and it is estimated to affect 3.8% of the population worldwide (World Health Organization 2021). Finding a cure for these disorders may not be a prime focus for the future but minimizing negative interactions with our modern environment could be one of the future avenues of research. In conclusion, understanding the evolutionary origins of mental disorders is essential for a thorough understanding of the problem and its possible solutions.