Disinhibition and risk compensation: scope, definitions, and perspective.

WITH MANY CHANGES, INCLUDING advances in health, comes speculation about the possible damaging and unintended consequences of introducing change. In many preventive interventions, unintended consequences follow a particular form called disinhibition or risk compensation. As typically understood, these concepts are operationalized via individuals who, once feeling protected against 1 health risk, engage in other risky behavior that puts them at risk for the same or other health problems. For example, commentary from the 1960s and 1970s cited effective STD treatment as a risk for increased sexual behavior.1 As well, recent debate over mandatory human papillomavirus vaccinations for school entry has brought similar fear that young women might subsequently feel free from concern about the cancer-causing disease and have more unprotected sex with more partners at an earlier age.2–4 In this issue of Sexually Transmitted Diseases, Greg et al. present data from a HIV prevention trial testing the safety and efficacy of oral tenofivir for women in Ghana,5 which we will use to prompt some thoughts about the differences between disinhibition and risk compensation and their scope and relationship to intervention. First, we note there are important conceptual differences between disinhibition and risk compensation with different implications for intervention strategies. Disinhibition derives from psychological terminology; it occurs when people stop trying to avoid risk to themselves or others. Probably the most widely known examples in sexual behavior are centered around the disinhibiting effects of alcohol; an inebriated person may be sexually incautious or aggressive because he or she no longer “cares” about the risk of sexual exposure.6,7 Other examples are drawn from people who feel they cannot avoid a harm and then no longer even try to do so.8 In both examples, the outcome is behavioral disinhibition through lack of caring, although the causes (alcohol vs. perception of unavoidable risk) are very different. Risk compensation, on the other hand, is best understood from a more cognitive perspective. The term applies to those whose diminished susceptibility via a given preventive intervention permits them to increase other risk behaviors. Although both terms are often used interchangeably in the literature, what we have defined as risk compensation is the most common source of concern for those conducting interventions. Guest et al.’s analysis of HIV preexposure prophylaxis in this issue5 is a good starting point to examine these phenomena more closely because the women in the trial, largely sex workers, (a) had high potential for disinhibition via greatly elevated–“unavoidable”–risk of HIV acquisition and (b) high potential for risk compensation via their economic motive for sex. Specifically, the authors examined changes in risk behavior among HIV negative, sexually active women after enrollment in the trial, with data gathered across up to 12 visits over the course of 6 months. For the purposes of these analyses, Guest et al. stratified the sample by baseline sexual risk characteristics (most risky 25% vs. all others); as both control and intervention arm participants took a pill daily, changes in risk would not easily be attributed to knowing one was on antiretroviral prophylaxis. They found that participants reported decreases in unprotected sex, with the steepest declines among women categorized (via number of partners and proportion of unprotected sex acts) in the highest risk group. Through qualitative interviews with a subset of the women, the authors were able to attribute decreased risk behavior at least partly to counseling accompanying the drug regimen. All this is good news about “changes in sexual behavior. ” The intervention provides another demonstration that most members of groups whose sexual health prospects have become more assured do not subsequently attempt to damage said prospects: that is, no widespread risk compensation was seen. Similarly, penicillin “preexposure prophylaxis” for syphilis, tested in Louisiana between 1997 and 1999, and a review of sexual behavior for HIV positive people on antiretroviral therapy yielded the same conclusions.9,10 Inference about disinhibition is more indirect, although the results are consistent with reduced disinhibition as the women’s protective behaviors increased with the advent of the preventive intervention. As with risk compensation, the qualitative data were supportive of such inferences but without ruling out alternative explanations. We do not suggest that risk compensation and disinhibition are always negligible effects in interventions. If one lesson seems to be that neither disinhibition nor risk compensation is a widespread, Correspondence: Matthew Hogben, PhD, Mail Stop E-44, Centers for Disease Control and Prevention, Atlanta, GA 30333. E-mail: mhogben@ cdc.gov. Received for publication August 1, 2008, and accepted September 19, 2008. From the Division of STD Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia Sexually Transmitted Diseases, December 2008, Vol. 35, No. 12, p.1009–1010 DOI: 10.1097/OLQ.0b013e31818eb752 Copyright © 2008, American Sexually Transmitted Diseases Association All rights reserved.