Adrian Carter

The phenomenological effects of deep brain stimulation (DBS) on the self of the patient remains poorly understood and under described in the literature, despite growing evidence that a significant number of patients experience postoperative neuropsychiatric changes. To address this lack of phenomenological evidence, we conducted in-depth, semistructured interviews with 17 patients with Parkinson's disease who had undergone DBS. Exploring the subjective character specific to patients' experience of being implanted gives empirical and conceptual understanding of the potential phenomenon of DBS-induced self-estrangement. Our study concluded that (1) the more patients preoperatively felt alienated by their illness, the more they experienced postoperative self-estrangement, and (2) the notion of self-estrangement seems to exist in association with certain common qualitative characters, namely, loss of control, which reflects a deteriorative estrangement, and distorted perception of capacities, which reveals a restorative estrangement. These findings indicate that subjective self-reports help us to understand some aspects of the potential phenomenon of DBS-induced self-estrangement.

In recent decades, researchers have attempted to prospectively identify individuals at high risk of developing psychosis in the hope of delaying or preventing psychosis onset. These psychosis risk individuals are identified as being in an ‘At-Risk Mental State’ (ARMS) through a standardised psychometric interview. However, disclosure of ARMS status has attracted criticism due to concerns about the risk–benefit ratio of disclosure to patients. Only approximately one quarter of ARMS patients develop psychosis after three years, raising concerns about the unnecessary harm associated with such ‘false-positive’ results. These harms are especially pertinent when identifying psychosis risk individuals due to potential stigma and discrimination in a young clinical population. A dearth of high-quality evidence supporting interventions for ARMS patients raises further doubts about the benefit accompanying an ARMS disclosure. Despite ongoing discussion in the bioethical literature, these concerns over the ethical justification of disclosure to ARMS patients are not directly addressed in clinical guidelines. In this paper, we aim to provide a unified disclosure strategy grounded in principle-based analysis for ARMS clinicians. After considering the ethical values at stake in ARMS disclosure, and their normative significance, we argue that full disclosure of the ARMS label is favoured in the vast majority of clinical situations due to the strong normative significance of enhancing patients' understanding. We then compare our framework with other approaches to ARMS disclosure and outline its limitations.

Gilbert et al. argue that the neuroethics literature discussing the putative effects of Deep Brain Stimulation on personality largely ignores the scientific evidence and presents distorted claims that personality change is induced by the DBS stimulation. This study contributes to the first-hand primary research on the topic exploring DBS clinicians’ views on post-DBS personality change among their patients and its underlying cause. Semi-structured interviews were conducted with sixteen clinicians from various disciplines working in Australian DBS practice for movement disorders and/or psychiatric conditions. Thematic analysis of the interviews revealed five primary themes: 1) types, frequency and duration of personality change, 2) causes of personality change, 3) impact on patient and family, 4) communication, comprehension and awareness, and 5) management. Clinicians described a variety of personality changes in Parkinson’s disease following DBS including irritability, impulsivity and impaired decision-making. The frequency of personality change seen in patients varied amongst clinicians, but changes were overwhelmingly transient. Clinicians considered both DBS stimulation and additional factors as inducing personality change. For DBS patients with major depressive disorder, a restoration of pre-morbid personality was associated with alleviation of illness. Considerations for future research of personality change following DBS include selecting suitable tools for quantitative examination and developing a common language between the scientific and ethics communities. Clinical implications including recommendations for the informed consent process for patients and families and clinicians’ management of personality change are discussed.

Gilbert et al. argue that the neuroethics literature discussing the putative effects of Deep Brain Stimulation on personality largely ignores the scientific evidence and presents distorted claims that personality change is induced by the DBS stimulation. This study contributes to the first-hand primary research on the topic exploring DBS clinicians’ views on post-DBS personality change among their patients and its underlying cause. Semi-structured interviews were conducted with sixteen clinicians from various disciplines working in Australian DBS practice for movement disorders and/or psychiatric conditions. Thematic analysis of the interviews revealed five primary themes: 1) types, frequency and duration of personality change, 2) causes of personality change, 3) impact on patient and family, 4) communication, comprehension and awareness, and 5) management. Clinicians described a variety of personality changes in Parkinson’s disease following DBS including irritability, impulsivity and impaired decision-making. The frequency of personality change seen in patients varied amongst clinicians, but changes were overwhelmingly transient. Clinicians considered both DBS stimulation and additional factors as inducing personality change. For DBS patients with major depressive disorder, a restoration of pre-morbid personality was associated with alleviation of illness. Considerations for future research of personality change following DBS include selecting suitable tools for quantitative examination and developing a common language between the scientific and ethics communities. Clinical implications including recommendations for the informed consent process for patients and families and clinicians’ management of personality change are discussed.

Gilbert et al. argue that the neuroethics literature discussing the putative effects of Deep Brain Stimulation on personality largely ignores the scientific evidence and presents distorted claims that personality change is induced by the DBS stimulation. This study contributes to the first-hand primary research on the topic exploring DBS clinicians’ views on post-DBS personality change among their patients and its underlying cause. Semi-structured interviews were conducted with sixteen clinicians from various disciplines working in Australian DBS practice for movement disorders and/or psychiatric conditions. Thematic analysis of the interviews revealed five primary themes: 1) types, frequency and duration of personality change, 2) causes of personality change, 3) impact on patient and family, 4) communication, comprehension and awareness, and 5) management. Clinicians described a variety of personality changes in Parkinson’s disease following DBS including irritability, impulsivity and impaired decision-making. The frequency of personality change seen in patients varied amongst clinicians, but changes were overwhelmingly transient. Clinicians considered both DBS stimulation and additional factors as inducing personality change. For DBS patients with major depressive disorder, a restoration of pre-morbid personality was associated with alleviation of illness. Considerations for future research of personality change following DBS include selecting suitable tools for quantitative examination and developing a common language between the scientific and ethics communities. Clinical implications including recommendations for the informed consent process for patients and families and clinicians’ management of personality change are discussed.

Deep brain stimulation of the subthalamic nucleus for the treatment of Parkinson’s disease can lead to the development of neuropsychiatric symptoms. These can include harmful changes in mood and behaviour that alienate family members and raise ethical questions about personal responsibility for actions committed under stimulation-dependent mental states. Qualitative interviews were conducted with twenty participants following subthalamic DBS at a movement disorders centre, in order to explore the meaning and significance of stimulation-related neuropsychiatric symptoms amongst a purposive sample of persons with PD and their spousal caregivers. Interview transcripts underwent inductive thematic analysis. Clinical and experiential aspects of post-DBS neuropsychiatric symptoms were identified. Caregivers were highly burdened by these symptoms and both patients and caregivers felt unprepared for their consequences, despite having received information prior to DBS, desiring greater family and peer engagement prior to neurosurgery. Participants held conflicting opinions as to whether emergent symptoms were attributable to neurostimulation. Many felt that they reflected aspects of the person’s “real” or “younger” personality. Those participants who perceived a close relationship between stimulation changes and changes in mental state were more likely to view these symptoms as inauthentic and uncontrollable. Unexpected and troublesome neuropsychiatric symptoms occurred despite a pre-operative education programme that was delivered to all participants. This suggests that such symptoms are difficult to predict and manage even if best practice guidelines are followed by experienced centres. Further research aimed at predicting these complications may improve the capacity of clinicians to tailor the consent process.

The misuse of alcohol inflicts a major toll on individual users, their families, and the wider society. This includes disruptions of family life, violence, absenteeism and problems in the workplace, child neglect and abuse, and excess morbidity and mortality. The World Health Organization estimates that alcohol ranks eighth among global risk factors for death and is the third leading global risk factor for disease and disability. In the United States, alcohol dependence affects four to five percent of the population at any given time. Alcohol dependence also exacts a significant financial toll....

Empirical research with Markov regime-switching models often requires the researcher not only to estimate the model but also to test for the presence of more than one regime. Despite the need for both estimation and testing, methods of estimation are better understood than are methods of testing. We bridge this gap by explaining, in detail, how to apply the newest results in the theory of regime testing, developed by Cho and White [Cho, J. S., and H. White 2007. “Testing for Regime Switching.” Econometrica 75 : 1671–1720.]. A key insight in Cho and White is to expand the null region to guard against false rejection of the null hypothesis due to a small group of extremal values. Because the resulting asymptotic null distribution is a function of a Gaussian process, the critical values are not obtained from a closed-form distribution such as the χ². Moreover, the critical values depend on the covariance of the Gaussian process and so depend both on the specification of the model and the specification of the parameter space. To ease the task of calculating critical values, we describe the limit theory and detail how the covariance of the Gaussian process is linked to the specification of both the model and the parameter space. Further, we show that for linear models with Gaussian errors, the relevant parameter space governs a standardized index of regime separation, so one need only refer to the tabulated critical values we present. While the test statistic under study is designed to detect regime switching in the intercept, the test can be used to detect broader alternatives in which slope coefficients and error variances may also switch over regimes.

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.