Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

The unintended consequences of argument dilution in direct-to-consumer drug advertisements


Direct-to-consumer (DTC) advertising of pharmaceutical drugs is often cited as the culprit for inflated patient demand for advertised drugs. Further to this economic concern, we provide an evidence-based psychological account of another concern that warrants the re-examination of the merits of DTC advertising of prescription drugs. Across six experiments and a sample of 3,059 US participants, we find reliable evidence for the argument dilution effect. Specifically, when commercials list severe side effects along with those that are most frequent (which include both serious and minor side effects), as required by the Food and Drug Administration, it dilutes consumers’ judgements of the overall severity of the side effects, compared with when only the serious side effects are listed. Furthermore, consumers’ reduced judgement of severity leads to greater attraction to those drugs. In regulating pharmaceutical advertisements, the Food and Drug Administration appear to have paradoxically dampened consumers’ judgements of overall severity and risk, and increased the marketability of these drugs.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Prices vary by article type



Prices may be subject to local taxes which are calculated during checkout

Fig. 1: The interaction effect of the two audio conditions and participants’ recall of major side effects on the perception of the drug’s overall side-effect severity (n = 804).


  1. Vastag, B. US aims to tighten rules on direct-to-consumer drug ads. Nat. Biotechnol. 25, 267–267 (2007).

    Article  CAS  PubMed  Google Scholar 

  2. Food and Drug Administration Regulatory Modernization Act of 1997, H.R. 1411, 105th Cong., 1st Sess. (1997);

  3. Mogull, S. A. Chronology of direct-to-consumer advertising regulation in the United States. Am. Med. Writ. Assoc. J. 23, 106–109 (2008).

  4. Pines, W. L. A history and perspective on direct-to-consumer promotion. Food Drug Law J. 54, 489–518 (1999).

    CAS  PubMed  Google Scholar 

  5. Mintzes, B. Direct to consumer advertising is medicalising normal human experience. BMJ 324, 908–911 (2002).

    Article  PubMed  PubMed Central  Google Scholar 

  6. Saul, S. Senate leader calls for limits on drug ads. The New York Times Politics (2 July 2005).

  7. Kahneman, D. & Tversky, A. On the psychology of prediction. Psychol. Rev. 80, 237–251 (1973).

    Article  Google Scholar 

  8. Nisbett, R. E., Zukier, H. & Lemley, R. E. The dilution effect: nondiagnostic information weakens the implications of diagnostic information. Cognit. Psychol. 13, 248–277 (1981).

    Article  Google Scholar 

  9. Zukier, H. Situational determinants of behavior. Soc. Res. 49, 1073–1091 (1982).

    Google Scholar 

  10. Zukier, H. & Jennings, D. L. Nondiagnosticity and typicality effects in prediction. Soc. Cogn. 2, 187–198 (1984).

    Article  Google Scholar 

  11. Meyvis, T. & Janiszewski, C. Consumers’ beliefs about product benefits: the effect of obviously irrelevant product information. J. Consum. Res. 28, 618–635 (2002).

    Article  Google Scholar 

  12. Troutman, C. M. & Shanteau, J. Inferences based on nondiagnostic information. Organ. Behav. Hum. Perform. 19, 43–55 (1977).

    Article  Google Scholar 

  13. Anderson, N. H. Integration theory and attitude change. Psychol. Rev. 78, 171–206 (1971).

    Article  Google Scholar 

  14. Anderson, N. H. Application of an additive model to impression formation. Science 138, 817–818 (1962).

    Article  CAS  PubMed  Google Scholar 

  15. Biegler, P. & Vargas, P. Ban the sunset? Nonpropositional content and regulation of pharmaceutical advertising. Am. J. Bioeth. 13, 3–13 (2013).

    Article  PubMed  Google Scholar 

  16. Petty, R. E. & Cacioppo, J. T. Communication and Persuasion 1–24 (Springer, New York, 1986);

  17. Zhao, X., Lynch, J. G. & Chen, Q. Reconsidering Baron and Kenny: myths and truths about mediation analysis. J. Consum. Res. 37, 197–206 (2010).

    Article  Google Scholar 

  18. MacKinnon, D. P., Krull, J. L. & Lockwood, C. M. Equivalence of the mediation, confounding and suppression effect. Prev. Sci. 1, 173–181 (2000).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  19. Schwartz, L. M. & Woloshin, S. The drug facts box: improving the communication of prescription drug information. Proc. Natl Acad. Sci. USA 110, 14069–14074 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  20. Aikin, K. J., O’Donoghue, A. C., Swasy, J. L. & Sullivan, H. W. Randomized trial of risk information formats in direct-to-consumer prescription drug advertisements. Med. Decis. Mak. 31, E23–E33 (2011).

    Article  Google Scholar 

  21. Deese, J. & Kaufman, R. A. Serial effects in recall of unorganized and sequentially organized verbal material. J. Exp. Psychol. 54, 180–187 (1957).

    Article  CAS  PubMed  Google Scholar 

  22. Spencer, S. J., Zanna, M. P. & Fong, G. T. Establishing a causal chain: why experiments are often more effective than mediational analyses in examining psychological processes. J. Pers. Soc. Psychol. 89, 845–851 (2005).

    Article  PubMed  Google Scholar 

  23. Relations, A. M. AMA calls for ban on direct to consumer advertising of prescription drugs and medical devices. American Medical Association (17 November 2015);

  24. Thaler, R. H. & Sunstein, C. R. Libertarian paternalism. Am. Econ. Rev. 93, 175–179 (2003).

    Article  Google Scholar 

  25. Daft, R. L. & Lengel, R. H. organizational information requirements, media richness and structural design. Manag. Sci. 32, 554–571 (1986).

    Article  Google Scholar 

Download references


The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript. We thank N. Ramkumar for assistance with materials for Study 2a.

Author information

Authors and Affiliations



N.S. developed the research idea. N.S. and H.K. designed the experiments; H.K. analysed the data; and N.S. and H.K. wrote the paper.

Corresponding author

Correspondence to Niro Sivanathan.

Ethics declarations

Ethics statement

The ethics approval for this project was provided by London Business School as per the school’s guidelines. In line with ethical guidelines, all participants provided informed consent before taking part in the studies.

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Electronic supplementary material

Supplementary Information

Supplementary Methods, Supplementary Table 1.

Life Sciences Reporting Summary

Life Sciences Reporting Summary

Rights and permissions

Reprints and Permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Sivanathan, N., Kakkar, H. The unintended consequences of argument dilution in direct-to-consumer drug advertisements. Nat Hum Behav 1, 797–802 (2017).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


Quick links

Nature Briefing: Translational Research

Sign up for the Nature Briefing: Translational Research newsletter — top stories in biotechnology, drug discovery and pharma.

Get what matters in translational research, free to your inbox weekly. Sign up for Nature Briefing: Translational Research