Psychiatric and Functional Physical Symptoms: The More Telling “Fifth” Vital Sign

Abstract

Historically, psychiatric symptomatology has been looked upon with a mixture of bewilderment and derision—the evidence of some kind of psychological or spiritual problem—but not of a medical or biological one. However, an explosion of new research suggests that psychiatric symptomatology may actually reveal as much about the physiological functioning of the body as heart rate, respiratory rate, temperature, and blood pressure. For example, there is growing evidence that psychiatric symptoms are associated with autonomic dysregulation and the early development of chronic debilitating diseases, such as diabetes, cardiovascular, hypertension, and cancer. These diseases then take the lives of the mentally ill at a much earlier age than the general population. In addition, an association has been found between upper-end-of-normal resting vital signs and the later development of major psychiatric illnesses, such as generalized anxiety disorder, obsessive-compulsive disorder, and schizophrenia. Notably, a similar association has been found between upper-end-of-normal resting vital signs and the early development of the same illnesses that shorten the lives of the mentally ill. These associations raise the possibility that subtle elevations in resting vital signs and psychiatric symptomology are different manifestations of a shared physiological abnormality. The identification of a core abnormality that influences such diverse emotional, psychological, and biological conditions could completely reshape the way we think about mental illness. It could unify mental disorders and medical disorders and raise psychiatric symptoms to the level of a “fifth” vital sign. This article will explore the links between mental illness, physical illness, and resting vital signs in an effort to utilize, if appropriate, psychiatric symptomatology as a barometer of physiological function. The unique value of psychiatric symptomatology in this regard is that it could reduce the need to distinguish psychiatric symptoms from medical symptoms while at the same time more clearly revealing, without any physical instrumentation, what is happening inside the body.