the issue of consent in research that administers drugs of addiction to addicted persons

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The Issue of Consent inResearch that AdministersDrugs of Addiction to AddictedPersonsAdrian Carter a & Wayne Hall Ph.D. ba The University of Queensland , Queensland BrainInstitute and the Department of Philosophy ,Queensland, Australiab The University of Queensland, School of PopulationHealth , Queensland, AustraliaPublished online: 29 Oct 2008.

To cite this article: Adrian Carter & Wayne Hall Ph.D. (2008) The Issue of Consent inResearch that Administers Drugs of Addiction to Addicted Persons, Accountability inResearch: Policies and Quality Assurance, 15:4, 209-225

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Accountability in Research, 15:209–225, 2008Copyright © Taylor & Francis Group, LLCISSN: 0898-9621 print / 1545-5815 onlineDOI: 10.1080/08989620802388689

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GACR0898-96211545-5815Accountability in Research, Vol. 15, No. 4, September 2008: pp. 1–24Accountability in Research THE ISSUE OF CONSENT IN RESEARCH THAT ADMINISTERS DRUGS OF ADDICTION

TO ADDICTED PERSONS

The Issue of Consent A. Carter and W. HallADRIAN CARTER1 and WAYNE HALL, PH.D.2

1The University of Queensland, Queensland Brain Institute and the Department of Philosophy, Queensland, Australia

2The University of Queensland, School of Population Health, Queensland, Australia

In addiction, impaired control over drug use raises questions about the capacityof addicted persons to consent to participate in research studies in which they aregiven their drug of addiction. We review the case for doing such research, andthe arguments that addiction does, and does not, prevent addicted persons fromconsenting to such research. We argue for a more nuanced view that acknowl-edges that while in some situations addiction impairs decision-making capacity,it does not eliminate such capacity. We conclude with some suggestions forrecruiting addicted subjects and designing experiments in ways to obtain freeand informed consent.

Keywords: addiction, addiction research, informed consent, neuroethics,research ethics

Introduction

The administration of addictive drugs to addicted participants canprovide valuable scientific information about the effects that thesedrugs have on motivation, learning and memory, and decision-making. Neuroimaging studies have identified changes in the brainfunction of addicted individuals that may underpin addictivebehavior and make cessation of drug use difficult. Such researchpromises to significantly improve our ability to treat addiction,and consequently, to reduce the significant personal and socialburden that it causes. Some bioethicists, however, have expressed

Address correspondence to Adrian Carter, The University of Queensland, QueenslandBrain Institute and Department of Philosophy, School of Biomedical Sciences, QLD 4072,Australia. E-mail: [email protected]

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210 A. Carter and W. Hall

doubts about the capacity of addicts to give free or internallyuncoerced consent to participate in these studies. If their argu-ments are accepted, neuroscientists would no longer be able toconduct this type of research. This area of neuroethics has receivedless attention than it deserves.

In this article we focus on the pressing issue of when, if at all,it is ethical to conduct research studies that administer drugs ofaddiction to addicted persons. We begin by describing the ratio-nale for this type of neuroscience research. We then review twocontrasting arguments that have dominated debate, namely, thataddicted individuals are incapable of giving free and informedconsent to participate in such research, and that addiction presentsno special problems for consent to research participation. We brieflyreview the neuroscientific and other research evidence that bearson these arguments. We then attempt to identify circumstancesin which addicts’ capacity to consent to research participationcan be impaired and provide some provisional guidelines on howaddicts may ethically participate in research that involves theadministration of an addictive substance. We conclude by high-lighting some areas for future research.

Why Do Neuroscientists Give Drugs to Addicts?

Neuroscience research over the last 50 years has had a signifi-cant impact on our understanding of the nature and origins ofaddiction (Volkow and Li, 2004; Koob and Le Moal, 2006; Nuttet al., 2007). Changes in brain function appear to explain theapparent inability of addicts to refrain from drug use despitethe negative consequences of continued use. Clinical neuro-science research has also increased our ability to treat addictionby increasing the range of pharmacological treatments that areavailable to assist addicts to become and remain abstinent(Iverson et al., 2007) (e.g., methadone and buprenorphine foropiate addiction, naltrexone and acamprosate for alcoholism,and bupropion and varenecline for nicotine addiction). Neuro-science research has the potential to provide even more effec-tive pharmacological treatments that have fewer side-effects andare better targeted to individual needs. More speculatively, ithas the potential to prevent addiction by identifying those whoare most vulnerable to developing addiction before they have

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The Issue of Consent 211

had an opportunity to use drugs (Volkow and Li, 2005; Hallet al., 2008; Lubman et al., 2008).

Human studies of the effect of drugs of addiction on brainstructure and function, in particular the visualization of thesechanges using neuroimaging (e.g., fMRI, PET, and EEG), havebeen critical to this endeavor. Research in animal models hasuncovered the central reward pathways of the brain on whichmost drugs of addiction appear to act (Koob and Le Moal,2006). While animal studies have elucidated the neuropharma-cology of reward that appears to be common to all mammals,they cannot be straightforwardly applied to the complex cognitiveand social behaviors in human drug addiction, such as subjectivecraving, impaired decision-making and impulse inhibition, andcompulsive use. Nor can animal studies determine whetherpromising drug treatments of addiction are safe and effective inaddicted humans (Geyer and Markou, 1995; Epstein et al., 2006;Fisch, 2007). There are in short significant evolutionary, cogni-tive, and cultural differences between highly controlled labora-tory animal models of addiction and the typical patterns ofaddictive drug use in humans. Human experimentation is neces-sary to bridge this gap.

The advent of affordable, noninvasive methods of neuroim-aging has permitted many of the neurobiological theories ofaddiction derived form animals to be tested, and in many cases,confirmed in human addicts (Garavan et al., 2007; Volkow et al.,2007). Neuroimaging has also highlighted significant changes inthe cortical centres of the human brain that underpin impair-ment of the higher order cognition unique to human addiction.The ability to directly visualize neurochemical changes in theaddicted human brain in response to addictive drugs has beencritical in improving our understanding of addiction and indeveloping new, more effective pharmacological treatments ofaddiction (Volkow et al., 2003).

While studies of the acute effects of addictive drugs, such asnicotine, heroin, alcohol, and cocaine, on normal human brainfunctioning raise ethically important issues of their own, thefocus of this article is on neuroimaging studies of the effects ofthese drugs on the brains of drug addicted persons. Similar eth-ical issues are raised by controlled clinical trials of treatmentsusing agonist drugs (drugs that act on similar brain sites and

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produce similar effects to typical drugs of addiction) (Charland,2002).

There is then a clear utilitarian justification for these types ofresearch, namely, that it has the potential to provide more effec-tive pharmacological treatments of addiction that will reduce theharm it causes to the individual and society more generally. Thepotential personal, social, and scientific benefits of neuroscienceresearch of addiction, however, are not sufficient to justifyresearch if it exploits a vulnerable population. We need to showthat those participating in such research are capable of consent-ing freely, that consent is obtained in ways that respects theirautonomy, and that there is an acceptable balance of risk andbenefit to addicted research participants.

Informed Consent to Research Participation

The respect for persons is a fundamental ethical principle thatvalues the autonomy and freedom of individuals to make theirown choices. In research, the respect for persons requires thatindividuals provide meaningful, fully informed, and voluntaryconsent to their participation (Faden et al., 1986). Informed con-sent is the process by which individuals agree to enter treatmentin the full knowledge of its possible risks and benefits, and in theabsence of duress or coercion. Informed consent to research par-ticipation is commonly taken to require that individuals: (1) havethe capacity to understand the risks and benefits of participatingin research and what their participation will involve, or cognitivecapacity, and (2) are free to make decisions (i.e., internally orexternally uncoerced) to participate, or volitional capacity (Fadenet al., 1986; Roberts, 2002; Walker et al., 2005).

There has been very little empirical research into the processof how informed the consent is that addicts provide when partici-pating in research on addiction (Sugarman et al., 1999). Studieshave focussed on the cognitive capacity of addicted individuals tocomprehend the risks and requirements of participating in research.Several studies have found that addicts, including injecting drugusers (IDUs), generally have the cognitive capacity to compre-hend and consent to participate in research (Harrison et al., 1995;Smith et al., 2006). These studies, however, have not assessed thevolitional capacity of addicts to provide free and internally uncoerced

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consent to participate in research or clinical trials that involve theconsumption of their drug of addiction. There has been verylittle research on volitional capacity to date, largely due to thedifficulty in measuring subjective phenomena such as desire,craving, or compulsion (Roberts, 2002).

Addiction is a highly stigmatized condition. This can encour-age negative stereotypes about the reasons why addicted personsparticipate in research, despite evidence suggesting that theirreasons for participation are similar to the general population(Fry and Dwyer, 2001). Presuppositions about addicts’ motivationfor research participation can color beliefs about their capacity toconsent to research that involves the administration of their drugof addiction. The limited bioethical discussion of this topic hasbeen based, largely, on a priori reasoning and “fireside induc-tions” in the absence of empirical evidence, as the following briefreview will show.

Can Addicts Say “No” to Drugs?

By definition, addiction is a disorder in which an individual’scontrol over their drug use is impaired. People who have anaddiction continue to use drugs in the face of serious negativeconsequences, and often despite expressing a wish that theycould stop. This apparent “loss of control” over drug use is codi-fied in the main international diagnostic criteria for addiction(World Health Organization, 1993; American Psychiatric Associ-ation, 1994).

The centrality of impaired control over drug use is empha-sized by neuroscientists who describe addiction as a “chronic,relapsing brain disease” (Leshner, 1997, p. 45). According to thismodel of addiction, the chronic self-administration of drugsproduces enduring changes in brain neurotransmitter systemsthat reinforce continued drug use, make it difficult for addicts torefrain from using drugs, and leave addicts vulnerable to relapseafter abstinence has been achieved (Volkow and Li, 2004).Adaptations to chronic drug use in the central reward pathwayare believed to reduce the sensitivity of addicted individuals tothe rewarding effects of natural reinforcers, such as, food, work,and relationships. Dysregulation of the prefrontal cortex is seento focus addicts’ attention primarily on drug use and to impair

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their ability to control their impulses to use drugs (Volkow andFowler, 2000; Volkow et al., 2003).

The “brain disease” model of addiction has been invoked bysome bioethicists who argue that persons with an addiction lackthe ability to make free and autonomous choices about participat-ing in research studies that involve the administration of theirdrug of addiction (Charland, 2002; Cohen, 2002; Elliott, 2002).Charland (2002), for example, has argued that heroin addicts areunable to give free and informed consent to participate in heroinprescription trials because they are incapable of saying “no” to theoffer of free heroin. The main warrants for his argument were thetestimony of one former heroin addict (“Cynthia”) and assertionsby addiction neuroscientists that the brains of opioid dependentindividuals are so altered by opioids that they are unable to considerthe risks of taking them. In using opioid drugs, Charland argues,“[t]heir decision is not truly theirs” (Charland, 2002, p. 43) and sothey are unable to consent to participate in clinical trials of inject-able heroin. One can imagine the same argument being used tooppose experimental studies that involve administering drugs ofaddiction to addicted individuals.

Charland’s claim that heroin users are unable to say “no” to anoffer of heroin was shown to be empirically false in the Swiss herointrials (Hall et al., 2003). The investigators were not inundated byuntreated heroin addicts seeking “free heroin,” as shown by thefailure of some studies to recruit the planned number of partici-pants. Moreover, in one study when heroin dependent subjectswere offered the choice of heroin maintenance or another treat-ment, only a minority chose heroin. These facts were evident in arandomized controlled trial that compared immediate access vs.delayed entry to heroin maintenance (with the delayed entrygroup given methadone maintenance or abstinence-orientedtreatment during the six months before being offered heroinmaintenance) (Perneger et al., 1998). The researchers intendedto recruit 40 patients in each group but were only able to recruit24 and 27 patients, respectively. When the subjects who wereallocated to delayed entry to heroin treatment were offered thechoice at the end of six months, two thirds decided against receiv-ing heroin (Perneger et al., 1998). Severely dependent, treatmentrefractory Swiss heroin addicts were thus capable of saying “no”to an offer of prescribed heroin.

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Contrary to Charland’s views, there is other evidence thataddicts are able to exert some control over their drug use. Theymay, and often do, stop using drugs without assistance for varyingperiods, either to reduce their tolerance or to take time out fromthe rigours of heroin use. In fact, many opioid addicts stop usingdrugs in response to major life events (e.g., the birth of a child,ultimatums from friends and family, or threats from employers)(Dalrymple, 2006). This demonstrates that addictive behavioris not merely the result of altered brain neurochemistry. Theexperience of returning Vietnam veterans who were able to quitopioid use without treatment once back in the U.S. is further evi-dence that opioid addiction is a more complex condition thansimplistic neuropharmacological models might be seen to suggest(Gerstein and Harwood, 1990).

In order for addiction to plausibly forestall autonomy, theinternal and external forces must be demonstrably irresistible.The evidence presented above suggests that this is not the case inall addicted individuals. Human neuroimaging and neurocogni-tive research show that addicts as a group show more disruptedbrain function in regions that are associated with a reduced abilityto control drug use and perform more poorly on tests of decisionmaking than nonaddicts. But these changes in brain function andneurocognitive deficits do not absolutely undermine capacity toconsent. Addicts have more diminished neurocognitive capacityand function than nonaddicts but not all addicts display thesedeficits while some nonaddicted controls do (Bechara et al.,2001; Bechara, 2005). For all these reasons, it would be mistakento conclude that all addicts are by definition incompetent toconsent to research that involves the administration of drugs ofaddiction.

Skeptical Views of Impaired Autonomy in Addicts

Other bioethicists have argued that addiction has no impact onthe ability of addicts to make autonomous decisions about druguse (Foddy and Savulescu, 2006). These authors argue thatneuroscience research shows that the motivation to use addictivedrugs is no different from other biological drives (e.g., the moti-vation to eat strawberries) (Foddy and Savulescu, 2006). This viewdiscounts two critical pieces of evidence on the neuropharmacology

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of addictive drugs. First, the effects of addictive drugs on brainfunctioning are supraphysiologically greater than those of naturalrewards like food (Volkow et al., 2004). These effects can confer amotivational salience on drug use that prevents everyday reward-ing activities from activating brain reward pathways. Second,chronic drug use also produces changes in the higher corticalareas of the brain that impair addicts’ capacity to inhibit thedesire to use drugs (Jentsch and Taylor, 1999; Grant et al., 2000;Fillmore, 2003; Hester and Garavan, 2004; Bechara, 2005).

Neuroscience research on addiction does not prove thataddicts lack the ability to make autonomous decisions about druguse, but it does suggest that their autonomy may be impaired insome situations (i.e., during acute withdrawal or intoxication; seebelow). This suggests that we need to move beyond simplisticeither/or debates about whether addiction always preventsaddicts from making free and uncoerced decisions about druguse in experimental settings. The strong assertion that addicts areby definition unable to make free and autonomous decisionsabout drug use is difficult to support. But it would be wrong tosuppose that there are no problems in obtaining consent fromaddicted individuals to participate in research that involvesadministering drugs of addiction. Researchers need to take theseimpaired capacities into account when designing experiments,recruiting addicted participants, and obtaining their consent toparticipate. They must look for ways to increase the autonomousdecision-making capacity of research participants, and thereforethe validity of their free and informed consent to participate. Wesuggest some provisional guidelines for further discussion anddebate.

The Risks of Giving Drugs to Addicts in Research Settings

Addiction neuroscientists have a responsibility to ensure thatresearch participation by addicted individuals carries minimalrisk. The degree of risk associated with research participation willdepend on the amount of drug provided, the route of administra-tion and the context in which it is given, the state of the participant(abstinent, detoxified, or drug using), length of study, monitoringof the participant’s condition during the study, and adequacy offollow-ups to detect adverse effects.

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Some have argued that the risks of participating in researchthat provides a drug of addiction are much lower than an addict’smore usual drug use. Nonabstinent drug addicted individualsoften engage in the chronic use of illicit drugs of unknownstrength and purity, often using the most hazardous route ofadministration (e.g., intravenous in suboptimal conditions usingpoor injection technique). In a research setting, by contrast,addictive drugs are provided under medical supervision by anappropriately qualified professional, using pharmaceutical medi-cations of known strength, and the dose is generally lower thanthat used recreationally (Adler, 1995). In a research setting, thereis also no risk normally associated with obtaining drugs, such asviolence or criminal conviction for possession of an illicit substanceor theft to fund an expensive habit. The relative risk of participat-ing in experiments that administer drugs of addiction is thereforemuch lower than the everyday risks run by a nonabstinent drugaddicted individual.

One concern has been that participation in research stud-ies may increase addicts’ drug use. This concern has been mostoften expressed about addicted subjects who have completed orare entering addiction treatment. The evidence from follow-upstudies suggests that research participation does not increasedrug use, or cause abstinent addicts to relapse (Faillace et al.,1972; Kranzler et al., 1990; Modell et al., 1993; Bigelow et al.,1994).

Most addicted subjects who participate in nontherapeuticresearch that administers addictive drugs derive some therapeu-tic benefit from their participation (Montoya and Haertzen,1994). At a minimum they receive a medical examination by ahealth professional in a supportive environment. They alsoreceive information about and access to treatment services andeducational material about drug use and addiction. TheNational Institute on Alcohol Abuse and Alcoholism (NIAAA)guidelines for research that administers alcohol to alcoholicsrecommends that “a serious and concerted effort should bemade to link alcohol dependent research subjects who are notin treatment with treatment services. This linkage should beactive in bringing together the subject with alcoholism treat-ment personnel” (National Advisory Council on Alcohol Abuseand Alcoholism, 1989).

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Consent During Withdrawal and Intoxication

Acute drug intoxication with commonly abuse drugs, such asopioids, alcohol, benzodiazepines, ecstasy, and amphetamines,can significantly impair an individual’s cognitive capacity, includ-ing their ability to comprehend the risks and requirements ofresearch participation (Curran, 1991; Finnigan and Hammerslay,1992; Curran et al., 2001; Mintzer et al., 2005). The “high”produced by these drugs can also affect an individual’s interest inthe consequences of research participation, thereby impairingtheir volitional capacity. The symptoms of acute drug withdrawalafter a period of voluntary or enforced abstinence can also pro-duce severe cognitive impairments (Lyvers and Yakimoff, 2003;Rapeli et al., 2006). Relief of withdrawal symptoms is a potentmotive for drug use that often over-rides an addict’s alreadyimpaired cognitive capacity. Consequently, drug dependent indi-viduals are unable to provide free and informed consent if theyare intoxicated or suffering acute withdrawal symptoms at thetime when consent is requested (Carter and Hall, 2008). Thereare standardized scales for assessing symptoms of drug intoxica-tion and withdrawal that should be used to assess the capacity ofaddicted individual’s to give consent (Dunn et al., 2006).

Research Participation of Treated vs. Untreated Addicts

The National Bioethics Advisory Council (1999) concluded thatonly addicted individuals who were not currently in treatmentshould be allowed to participate in research that involved adminis-tering their drug of addiction (National Bioethics Advisory Com-mission, 1999). This view has been contested by Cohen (2002). Hehas argued to the contrary that only addicts who have entered, orintend to enter treatment, have the capacity to freely consent toparticipate in research that involves administering addictive drugs.Cohen argues that by entering treatment, addicts demonstrate thatthey are able to make autonomous and voluntary decisions abouttheir drug use. He claims that because of the impact that addictionhas upon affected individuals, those that continue to use drugs areoften “in denial” about their condition, and therefore lack theinsight to make autonomous decisions about research participa-tion. Cohen provides no empirical evidence for this claim.

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There are several problems with Cohen’s argument. First, itis unwise to assume that the only competent choice an addict canmake is not to use drugs. We generally hold people as competent,and hence responsible for other harmful choices, such as drunkdriving. The choice to use a drug under the medical supervisionprovided in a research study could be construed as a moreinformed choice than the decision to use an illicit drug withoutmedical supervision.

Second, we should not assume that an individual who contin-ues to abuse drugs despite serious negative consequences is indenial about their condition. Many addicts are aware of the impactthat their drug use is having but continue to use drugs becausethey prefer to sacrifice long-term harm for short term gain; theyheavily discount future consequences in preference to the shortterm gain of the drug’s effects (Elster and Skog, 1999).

Third, the decision to enter treatment may be an indicationthat the individual is not beholden to strong drug cravings, andhence possesses the volitional capacity to choose whether or notto participate in research. But it does not guarantee that theirchoice is free. Many addicted individuals enter treatment as aresult of some form of coercion, whether from courts, friends orfamilies, or employers. An addicted individual who agrees to par-ticipate in a research study in the absence of external coercioncould arguably be making a more autonomous and internallyuncoerced decision than someone entering treatment in a stateof withdrawal and under legal duress.

Fourth, it is more difficult than Cohen assumes to define anaddict who is being “treated.” Cohen implicitly assumes that anaddict who enters treatment will from that time forward refrain fromusing drugs. In fact, most will relapse at some point. The neuropsy-chological changes that underpin relapse have been demonstratedin addicts who have been abstinent for months (Childress et al.,1999). A decision to enter treatment does not therefore ensure thatan addict has the capacity to resist desires to use drugs or to consentto research offering them access to their drug of addiction.

Recruiting Subjects and Obtaining Consent

Anyone who conducts research with addicted participants shoulddesign their experiments and participant recruitment strategies to

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increase the autonomous decision-making capacity of prospectiveparticipants. This would involve minimizing situations that mayelicit strong, over-powering urges or cravings for drugs that mayimpair the ability of addicts to make free decisions about partici-pation in experiments that administer drugs of addiction. Thereare a number of ways that researchers could do so.

First, when advertising for participants researchers shouldminimize any expectation among potential participants that theywill receive an addictive drug. This would reduce the number ofparticipants whose major reasons for research participation wasto acquire drugs. Advertisements should avoid any mention ofdrug use. Study descriptions could emphasize that participantsare not assured of receiving a drug by indicating that they may beassigned to a control group that does not receive drugs.

Second, researchers should avoid administering drugs shortlyafter obtaining participants’ consent (Walker, 2008). The partici-pant’s belief that a drug of addiction will be immediately madeavailable may trigger strong cravings that overwhelm rationalappraisal of the risks and benefits of participation for all thereasons outlined above. The possibility of drug administration atsome later time (e.g., in one or two weeks) is less likely to over-whelm rational thought. Craving is a strong urge that begs imme-diate gratification and impairs rational thought about what to doin the immediate future (Elster and Skog, 1999). The strengthand immediacy of the urge to take drugs may mean that individu-als who are strongly affected by craving are less likely to persistwith time consuming consent procedures or delays in receivingtheir drug of choice. They are more likely to spend their timeacquiring their drug by conventional means (e.g., illicit drugmarkets). Removing the arousal of immediate drug use would givetime for craving to pass, and thereby allow for a more rationalapproach to consent (Walker, 2008).

Third, researchers should obtain participants’ consent inways that minimize stress and cognitive load that can impairautonomous choices (Baumeister, 2003; Levy, 2006). This couldbe accomplished by using audiovisual tools that can increasecomprehension or ease stress, and thus maximize the capacity ofaddicted individuals to consent to research (Fureman et al.,1997; Dunn and Jeste, 2001). More research is required on howbest to do so. There has been very little research in this regard,

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with only one study identified examining ways to improve consentto research in substance abusing populations (Fureman et al.,1997).

Fourth, researchers should also consider including simpletests of decision-making capacity in the consent process. Testsof cognitive capacity (e.g., Mini-mental state examination) havebeen shown to be effective (Hazelton et al., 2003; Cairns et al.,2005; Hotopf, 2005; Smith et al., 2006), but at present thereare no validated measures of volitional capacity, although theMacArthur Competence Assessment Tools for Clinical Research(M-CAT) shows some promise (Dunn et al., 2006). Such testswould be useful in ensuring that an individual has the freedom toconsent to research participation (Dunn et al., 2006).

Conclusion

Addicted individuals arguably have the same right to participatein and benefit from scientific research into their condition, asanyone afflicted by any other medical disorder. The views thataddicts lack the capacity to give free and informed consentwould, if accepted, significantly hinder research on addiction,and hence the development and evaluation of new treatmentsthat may benefit addicted persons. This would not only be a viola-tion of the principle of justice (equal distribution of the benefitsof research) but it would, from a utilitarian point of view, lead topoorer outcomes for addicted individuals. We need to be mindfulof well-intended but overly paternalistic policies that deny addictsthe right to participate in research.

We also need to acknowledge, however, that addiction canimpair decision-making. This is clearest when addicts are intoxi-cated or in acute withdrawal. Apart from these acute states, webelieve that while addiction can impair autonomy it does not, bydefinition, preclude addicts from making free and uncoercedchoices about drug use in experimental settings. Researchers andpolicy makers still have a moral obligation to ensure that therights of addicted individuals are protected and their autonomyin research participation is maximized.

Researchers and ethicists need to avoid over simplifiedconclusions that encompass all addicted individuals (e.g., theopposing views that all addicts are or are not incapable of giving

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free and informed consent). We need to develop more nuancedviews that begin with the presumption that addicts possess somedecision making capacity and attempt to build on that capacity byrecruiting addicted research participants and obtaining consentin ways that engage them as much as possible in making decisionsabout whether or not to participate in research studies thatinvolve administering drugs of addiction. To achieve this end, weneed more research on the impact that cognitive impairment andstrong urges to use drugs have on the volitional capacity of addictsin different stages of addiction, and in different research andclinical contexts.

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the issue of consent in research that administers drugs of addiction to addicted persons

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