Adrian Carter

Impaired control over drug use is a defining characteristic of addiction in the major diagnostic systems. However there is significant debate about the extent of this impairment. This qualitative study examines the extent to which leading Australian addiction neuroscientists and clinicians believe that addicted individuals have control over their drug use and are responsible for their behaviour. One hour semi-structured interviews were conducted during 2009 and 2010 with 31 Australian addiction neuroscientists and clinicians (10 females and 21 males; 16 with clinical experience and 15 with no clinical experience). Although many addiction neuroscientists and clinicians described uncontrolled or compulsive drug use as characteristic of addiction, most were ambivalent about whether or not addicted people could be said to have no control of their drug use. Most believed that addicted individuals have fluctuating levels of impaired control over their drug use but they nonetheless believed that addicted persons were responsible for their behaviour, including criminal behaviour engaged in to fund their drug use. Addiction was not seen as exculpating criminal behaviour but as a mitigating factor

The authors comments on several articles on addiction. Research suggests that addicted individuals have substantial impairments in cognitive control of behavior. The authors maintain that a proper study of addiction must include a neurobiological model of addiction to draw the attention of bioethicists and addiction neurobiologists. They also state that more addiction neuroscientists like S. E. Hyman are needed as they understand the limits of their research. Accession Number: 24077921; Authors: Carter, Adrian 1; Email Address: [email protected] Hall, Wayne 1; Affiliations: 1: The University of Queensland, Brisbane, Australia; Subject: EDITORIALS; Subject: ADDICTIONS; Subject: BEHAVIOR; Subject: HYMAN, S. E.; Subject: NEUROBIOLOGISTS; Subject: NEUROSCIENTISTS; Number of Pages: 3p

There is growing evidence that dopamine replacement therapy (DRT) used to treat Parkinson’s Disease can cause compulsive behaviours and impulse control disorders (ICDs), such as pathological gambling, compulsive buying and hypersexuality. Like more familiar drug-based forms of addiction, these iatrogenic disorders can cause significant harm and distress for sufferers and their families. In some cases, people treated with DRT have lost their homes and businesses, or have been prosecuted for criminal sexual behaviours. In this article we first examine the evidence that these disorders are caused by DRT. If it is accepted that DRT cause compulsive or addictive behaviours in a significant minority of individuals, then the following ethical and clinical questions arise: Under what circumstances is it ethical to prescribe a medication that may induce harmful compulsive behaviours? Are individuals treated with DRT morally responsible and hence culpable for harmful or criminal behaviour related to their medication? We conclude with some observations of the relevance of DRT-induced ICDs for our understanding of addiction and identify some promising directions for future research and ethical analysis

Addiction is increasingly described as a “chronic and relapsing brain disease”. The potential impact of the brain disease model on the treatment of addiction or addicted individuals’ treatment behaviour remains uncertain. We conducted a qualitative study to examine: (i) the extent to which leading Australian addiction neuroscientists and clinicians accept the brain disease view of addiction; and (ii) their views on the likely impacts of this view on addicted individuals’ beliefs and behaviour. Thirty-one Australian addiction neuroscientists and clinicians (10 females and 21 males; 16 with clinical experience and 15 with no clinical experience) took part in 1 h semi-structured interviews. Most addiction neuroscientists and clinicians did not uncritically support the use of brain disease model of addiction. Most were cautious about the potential for adverse impacts on individuals’ recovery and motivation to enter treatment. While some recognised the possibility that the brain disease model of addiction may provide a rationale for addicted persons to seek treatment and motivate behaviour change, Australian addiction neuroscientist and clinicians do not assume that messages about “diseased brains” will always lead to increased treatment-seeking and reduced drug use. Research is needed on how neuroscience research could be used in ways that optimise positive outcomes for addicted persons

Deep brain stimulation (DBS) has been proposed as a potential treatment of drug addiction on the basis of its effects on drug self-administration in animals and on addictive behaviours in some humans treated with DBS for other psychiatric or neurological conditions. DBS is seen as a more reversible intervention than ablative neurosurgery but it is nonetheless a treatment that carries significant risks. A review of preclinical and clinical evidence for the use of DBS to treat addiction suggests that more animal research is required to establish the safety and efficacy of the technology and to identify optimal treatment parameters before investigating its use in addicted persons. Severely addicted persons who try and fail to achieve abstinence may, however, be desperate enough to undergo such an invasive treatment if they believe that it will cure their addiction. History shows that the desperation for a cure of addiction can lead to the use of risky medical procedures before they have been rigorously tested. In the event that DBS is used in the treatment of addiction, we provide minimum ethical requirements for clinical trials of its use in the treatment of addiction. These include: restrictions of trials to severely intractable cases of addiction; independent oversight to ensure that patients have the capacity to consent and give that consent on the basis of a realistic appreciation of the potential benefits and risks of DBS; and rigorous assessments of the effectiveness and safety of this treatment compared to the best available treatments for addiction

Lewis’ neurodevelopmental model provides a plausible alternative to the brain disease model of addiction that is a dominant perspective in the USA. We disagree with Lewis’ claim that the BDMA is unchallenged within the addiction field but we agree that it provides unduly pessimistic prospects of recovery. We question the strength of evidence for the BDMA provided by animal models and human neuroimaging studies. We endorse Lewis’ framing of addiction as a developmental process underpinned by reversible forms of neuroplasticity. His view is consistent with epidemiological evidence of addicted individuals ‘maturing out’ and recovering from addiction. We do however hold some reservations about Lewis’ model. We do not think that his analysis of the neurobiological evidence is clearly different from that of the BDMA or that his neurodevelopmental model provides a more rigorous interpretation of the evidence than the BDMA. We believe that our understanding of the neurobiology of drug use is too immature to warrant the major role given to it in the BDMA. Our social research finds very mixed support for the BDMA among addicted people and health professionals in Australia. Lewis’ account of addiction requires similar empirical evaluation of its real-world implications.