Deep brain stimulation (DBS) to different sites allows interfering with dysfunctional network function implicated in major depression. Because a prominent clinical feature of depression is anhedonia--the inability to experience pleasure from previously pleasurable activities--and because there is clear evidence of dysfunctions of the reward system in depression, DBS to the nucleus accumbens might offer a new possibility to target depressive symptomatology in otherwise treatment-resistant depression. Three patients suffering from extremely resistant forms of depression, who did not respond to pharmacotherapy, psychotherapy, (...) and electroconvulsive therapy, were implanted with bilateral DBS electrodes in the nucleus accumbens. Stimulation parameters were modified in a double-blind manner, and clinical ratings were assessed at each modification. Additionally, brain metabolism was assessed 1 week before and 1 week after stimulation onset. Clinical ratings improved in all three patients when the stimulator was on, and worsened in all three patients when the stimulator was turned off. Effects were observable immediately, and no side effects occurred in any of the patients. Using FDG-PET, significant changes in brain metabolism as a function of the stimulation in fronto-striatal networks were observed. No unwanted effects of DBS other than those directly related to the surgical procedure (eg pain at sites of implantation) were observed. Dysfunctions of the reward system--in which the nucleus accumbens is a key structure--are implicated in the neurobiology of major depression and might be responsible for impaired reward processing, as evidenced by the symptom of anhedonia. These preliminary findings suggest that DBS to the nucleus accumbens might be a hypothesis-guided approach for refractory major depression. (shrink)

Although an invasive medical intervention, Deep Brain Stimulation (DBS) has been regarded as an efficient and safe treatment of Parkinson’s disease for the last 20 years. In terms of clinical ethics, it is worth asking whether the use of DBS may have unanticipated negative effects similar to those associated with other types of psychosurgery. Clinical studies of epileptic patients who have undergone an anterior temporal lobectomy have identified a range of side effects and complications in a number of domains: psychological, (...) behavioural, affective and social. In many cases, patients express difficulty adjusting from being chronically ill to their new status as ‘treated’ or ‘seizure free’. This postoperative response adjustment has been described in the literature on epilepsy as the ‘Burden of Normality’ (BoN) syndrome. Most of the discussion about DBS postoperative changes to self is focused on abnormal side effects caused by the intervention (ie, hypersexuality, hypomania, etc). By contrast, relatively little attention is paid to the idea that successfully ‘treated’ individuals might experience difficulties in adjusting to becoming ‘normal’. The purpose of this paper is (1) to articulate the postoperative DBS psychosocial adjustment process in terms of the BoN syndrome, (2) to address whether the BoN syndrome illustrates that DBS treatment poses a threat to the patient’s identity, and (3) to examine whether the current framework for rehabilitation after DBS procedures should be updated and take into account the BoN syndrome as a postoperative self-change response. (shrink)

The goal of this article is to shed light on Deep Brain Stimulation (DBS) postoperative suicidality risk factors within Treatment Resistant Depression (TRD) patients, in particular by focusing on the ethical concern of enrolling patient with history of self-estrangement, suicide attempts and impulsive–aggressive inclinations. In order to illustrate these ethical issues we report and review a clinical case associated with postoperative feelings of self-estrangement, self-harm behaviours and suicide attempt leading to the removal of DBS devices. Could prospectively identifying and excluding (...) patients with suicidality risk factors from DBS experimental trials—such as history of self-estrangement, suicide attempts and impulsive–aggressive inclinations—lead to minimizing the risk of suicidality harm? (shrink)