Funding information: National Science Foundation, Grant/Award Number: BCS 1355469
The germ theory of disease and the attendant public health initiatives, including sanitation, vaccination, and antibiotic treatment, led to dramatic increases in global life expectancy. As the prevalence of infectious disease declines, mental disorders are emerging as major contributors to the global burden of disease. Scientists understand little about the etiology of mental disorders, however, and many of the most popular psychopharmacological treatments, such as antidepressants and antipsychotics, have only moderate‐to‐weak efficacy in treating symptoms and fail to target biological systems that correspond to discrete psychiatric syndromes. Consequently, despite dramatic increases in the treatment of some mental disorders, there has been no decrease in the prevalence of most mental disorders since accurate record keeping began. Many researchers and theorists are therefore endeavoring to rethink psychiatry from the ground‐up. Anthropology, especially biological anthropology, can offer critical theoretical and empirical insights to combat mental illness globally. Biological anthropologists are unique in that we take a panhuman approach to human health and behavior and are trained to address each of Tinbergen’s four levels of analysis as well as culture. The field is thus exceptionally well‐situated to help resolve the mysteries of mental illness by integrating biological, evolutionary, and sociocultural perspectives.
During the 20th century, the biomedical sciences rapidly reduced the global burden of infectious disease, leading to dramatic increases in life expectancy (Murray et al., 2015). In the 21st century, chronic, non‐infectious diseases have emerged as major contributors to global disease burden (Benziger, Roth, & Moran, 2016), with mental disorders playing a substantial role (Whiteford et al., 2013). The causes of most mental disorders, however, remain a mystery, and there has been little progress in reducing the prevalence of any of them.
Here we provide a comprehensive critique of mainstream research on mental disorders (see Figure 1). First, we review the contribution of mental disorders to the global burden of disease. Second, we explore the successes and failures of biological psychiatry, including psychopharmacology, imaging and other biomarker research, and genetic and epigenetic approaches. Third, we critique the theoretical foundations of psychiatric classification, reviewing different concepts of disorder and disease. Our goal in the first half of our article is to convince biological anthropologists that there is a genuine and widely‐recognized theoretical crisis in mental health research.
In the second half of our article, we sketch new approaches to mental health research from within mainstream psychiatry and clinical psychology, some of which are driven by the National Institute of Mental Health (NIMH). We then offer a provisional evolutionary schema for conceptualizing mental disorders that identifies one group as relatively rare disorders of development that are probably caused by genetic variants, one widespread group that comprises aversive but probably adaptive responses to adversity and therefore are likely not disorders at all, one group that is probably due to senescence, and one group that might be caused by mismatches between ancestral and modern environments. For each group, we review biocultural studies of mental health that provide fresh insights. Biological anthropologists are unique among the health‐related researchers in that we take a panhuman approach to human health and behavior and are trained to address each of Tinbergen’s four levels analysis (mechanistic, ontogenetic, phylogenetic, and function; for historical overview, see Beer, 2019) as well as culture. Thus, our field is exceptionally well‐situated to help resolve the mysteries of mental disorders by integrating biological, evolutionary, and sociocultural perspectives.