Medicine has a long and complex past that mirrors the course of human history. Indeed, the major historical milestones of medicine cannot be understood outside of cultural context. A current of reductionist thought flows throughout the history of medicine, and has been pivotal in identifying and defining disease, and directing treatment into specialized, highly developed fields. However, this may have led to the creation of artificial boundaries around assessment and management, resulting in fractured, and at times, sub-optimal patient care. A more contemporary approach has reconceptualized the patient within a larger clinical and practical context. This transition demonstrates the value of an interdisciplinary approach, in which the patient, rather than the illness is the focus of treatment rather than the identified illness. There is also a transition toward a greater mechanistic understanding of illnesses. These developments have resulted in a greater appreciation of the overlap between physical and mental health, two areas which have at times occupied opposite poles of medical practice due to dualistic thinking, but which undeniably influence one another and can never be fully disentangled.
This textbook focuses its lens at this interface, examining the relationship between medical disorders and the most ubiquitous mental illness, depression. The associations between medical illness and depressive illness now appear to be more extensive and more intimate than previously appreciated. These associations may be considered coincidental, causal, or the result of a common underlying pathological process. The implications of these associations are shifting clinical practice in a new and more unified direction.
In this chapter, we will review differential diagnosis of depressive disorders within medically ill populations, including brief considerations of screening and treatment of depression in medical settings and an approach for stratification and treatment that can be implemented in both inpatient and outpatient settings. This discussion is followed by a closer examination of the relationship between depression and medical illness, reviewing diseases and treatments known to cause depression and examining depression as a final common pathway for both emotional and physiological disturbances. Finally, we review the synergistic effects of depression and medical illness, ranging from diminished functional status and decreased quality of life to increased rates of suicide and other forms of physical mortality. Although treatment is not a specific focus of this chapter and is covered in great depth later in this textbook, this chapter reiterates key themes of early intervention and collaborative care, as such principles of treatment can be implemented in the medical setting and are critical to optimizing outcomes.
In order to best appreciate the current understanding of depression in medically ill patients, it is helpful to begin with an historical perspective. This review reflects the natural evolution of man's approach to “madness.” Early pioneers in the field produced rich descriptions of psychopathology, whereas later generations would propose causal mechanisms and modes of treatment.
Historical accounts of what constitutes ...