Where when and why do we see placebo effects

In virtually all areas of medicine, placebo effects exist. Clinical lore suggests that when a battlefront physician ran out of morphine, saline was found to have an equivalent effect. Certainly there are chronic deteriorating malignant disorders with virtually no placebo effects. However, for most psychiatric disorders, placebo effects do exist.

The unpredictable course of psychiatric disorders and a nosology with limited reliability and validity contribute to the placebo response rate. The development of DSM-III, an atheoretical and phenomenologically based nosological system, is an important milestone for psychiatry. (11.) Certainly, this reduces sample heterogeneity and helps to narrow the range of placebo response: that is, there are samples we would anticipate as having high placebo response rates, transient dysphoria, or low placebo response (severe melancholia). However, diagnoses not based on disease pathophysiology must be inexact and include phenocopies with different prognoses. The fact that the placebo response rate varies from 25 to 60 per cent for samples of patients with major depressive disorder is an expression of this problem.(1 l3!5 and 16) Furthermore, even if the pathophysiological basis of a disorder is understood, host (namely, individual resistance) and other poorly defined factors typically make the course of the illness variable. Human immunodeficiency viral infection is a case in point. (16> Prior to the development of effective treatments some infected individuals survived 15 or more years, others had a rapid demise. Analogous unidentified prognostic factors contribute to the variable prognosis of psychiatric disorders. Thus, the difficulties in assessing a treatment's utility in other areas of medicine are compounded by the limitations of our phenomenologically based nosological system and lack of knowledge of the pathophysiology of psychiatric disorders. Factors associated with a placebo response are considered further in Chapter. 5.7.

Beat Depression Now

Beat Depression Now

Let me be up front. My intention is to sell you something. Normally, it's not wise to come out and say that. However, I can do so because I have such an incredible deal for you that you'd be crazy to pass on it.

Get My Free Ebook


Post a comment