Are the colors and shapes of current psychotropics designed to maximize the placebo response?

Abstract

Rationale

Patient expectations are an important aspect of the placebo response. Color and shape of a medication lead to perceptions that an agent is stimulating or calming, strong or weak.

Objectives

We assessed the degree to which central nervous system medications match the perceived drug action and thereby harness the placebo response.

Methods

We consulted the 2009 Physicians’ Desk Reference and recorded the formulation and color of each referenced dose of central nervous system therapeutics approved for sale in the USA. On the basis of the expectations they engender, orange, yellow, and red pills were categorized stimulating; green, blue, and purple pills calming. White and gray pills were considered neutral.

Results

The majority of the 176 unique doses that were included in the study were in tablet (55%) and capsule (33%) form. Stimulants (75%) were the only drug category primarily formulated as capsules. Of the 176 unique doses included, 43% were stimulating, 23% calming, 23% neutral, and 12% were a formulation other than pill or capsule. There were no instances in which over 50% of the pills of an indication were stimulating or calming in color.

Discussion

Our study did not confirm the hypothesis that pharmaceutical companies color and formulate the shape of drugs to enhance the treatment response. In several instances, each approved dose of a given medication was a different color, and the majority of doses were in tablet form. Further research into the effect of different colors and formulations of medications on perceptions and efficacy evaluations should be considered.

Appendix

Table 2 Dose, formulation, color, and expectancy of FDA-approved antidepressants referenced in 2009 Physicians’ Desk Reference product classification index

Table 3 Dose, formulation, color, and expectancy of FDA-approved anxiolytics referenced in 2009 Physicians’ Desk Reference product classification index

Table 4 Dose, formulation, color, and expectancy of FDA-approved sedatives referenced in 2009 Physicians’ Desk Reference product category index

Table 5 Dose, formulation, color, and expectancy of FDA-approved anti-panic agents referenced in 2009 Physicians’ Desk Reference product classification guide

Table 6 Dose, formulation, color, and expectancy of FDA-approved anti-mania agents referenced in 2009 Physician Desk Reference product classification index

Table 7 Dose, formulation, color, and expectancy of FDA-approved antipsychotics referenced in 2009 Physicians’ Desk Reference product category index

Table 8 Dose, formulation, color, and expectancy of FDA-approved stimulants referenced in 2009 Physicians’ Desk Reference product category index