Brain figure and small figures of  doctors
Adobe Stock/Sirichai Puangsuwan

Psychiatric neurosurgery (PNS) is defined as neurosurgery intended for treating psychiatric disorders for which the biological underpinnings are unknown, and are not directly caused by brain diseases, such as brain tumors or epileptogenic tissues.Until the 1970s, crude forms of “psychosurgery” had been used in many mentally ill patients, but following public criticism and the development of anti-psychotic drugs, psychosurgery became nearly abandoned, and was forbidden in many countries.

Comeback of psychiatric neurosurgery since 2010

However, since 2010, there is a renaissance of psychiatric neurosurgery, albeit in a much more refined and safer form. Contemporary PNS procedures include deep brain stimulation (DBS) and ablative neurosurgical procedures. In DBS, there is permanent current delivery to specific areas of the brain through thin electrodes, in order to activate or deactivate these brain areas. The ablative neurosurgical procedures comprise of thermal or radiofrequency ablation procedures, and radiosurgery (Gamma Knife radiosurgery and MR guided focused ultrasound). These procedures create tiny lesions in brain areas, which play a crucial role in psychiatric symptoms.

Ethical issues remain

Although these modern forms of psychiatric neurosurgery have lesser adverse effects and risks, and are much more precise due to neuroimaging studies, many ethical issues remain. For example, is it justified to intervene in the brain of mentally ill patients when it might change their personality and behavior? What is the risk-benefit-ratio for the patients? For which kinds of disorders can the use of PNS be justified – also for drug addiction or anorexia nervosa? In addition, many legal questions are open.

About the project

The PNS consortium has brought together a multi-national team to investigate ethical, legal and societal issues of PNS. In contrast to previous projects, all psychiatric neurosurgical procedures were compared and evaluated, not only deep brain stimulation but also ablative procedures. Completely new procedures such as MR-guided focused ultrasound as well as procedures that are still in preclinical research (optogenetics) were also investigated. The consortium was coordinated by Sabine Müller from Germany and included Tade Matthias Spranger from Germany, Judy Illes from Canada, Roberto Martínez-Álvarez from Spain and Chris Bervoets from Belgium (more about the role of each partner in the consortium is described below).

We recommend that methods with good evidence for effectiveness and an acceptable risk profile should be rapidly transferred into clinical practice… For each patient, the risks and benefits of surgery must be balanced with the risks and benefits of continuing with treatment as usual.
Müller et al. (2022)

Project outcomes

One of the outcomes of the above research project is a recent publication in the journal Neuroethics, by the German, Belgian and Spanish project partners. In this review, the authors identify the main concerns about PNS, from patients and psychiatrists alike, the extent to which these concerns are justified and how they might be overcome, followed by providing recommendations on how to proceed with responsible research in PNS in accordance with the highest scientific and ethical demands.

Four main concerns were mapped:

  1. reservations based on historical psychosurgery; this concern refers mainly to ablative PNS;
  2. concerns about personality changes;
  3. concerns regarding localized interventions as opposed to a holistic approach;
  4. skepticism due to the lack of scientific evidence.

These concerns are addressed and recommendations for research and care are provided in the review. In this work, the ethics team and the clinical partners of the consortium have worked out and published recommendations for an ethically, legally and societally justifiable development of psychiatric neurosurgery.

Without the support of ERA-Net NEURON, this collaboration project would not have come into being. The dedicated ELSA calls for proposals in neuroscience are very important, because otherwise ELSA research proposals on neuroscience topics would be unlikely to be considered for funding in general ELSA calls.
Sabine Müller (Coordinator of the PNS consortium)

PNS consortium partners and roles:

Sabine Müller (Germany):

The ethics project has critically analyzed the broad ethical debate about DBS as a threat to personal identity, and investigated the understanding of autonomy in the light of neuropsychiatry and neurotechnology. We have argued that the ethically decisive question is not whether psychiatric neurosurgery can change the personality or not, but whether it does so in a good or bad way, i.e., first whether the result of change is good or bad; second whether the way of change is good or bad. Consequently, personality changes through interventions in the brain can be considered as ethically problematic if they (i) occur against the patient’s will, (ii) harm either the patient or third persons, (iii) reduce the patient’s capacity for autonomy, or (iv) diminish valuable abilities. Whereas negative personality changes should be avoided, positive personality changes should be accepted or even encouraged, regardless of whether they are of natural or surgical origin.

Furthermore, we have analyzed and compared the scientific evidence for the efficacy and safety of different approaches of PNS for different mental disorders, and evaluated their advantages and disadvantages for patients. We found preliminary evidence for efficacy and an acceptable risk-benefit profile for DBS and for micro- or radiosurgical anterior capsulotomy for intractable obsessive-compulsive disorder. We recommend to consider these methods for individual treatment attempts. However, multi-centre randomized controlled trials are necessary to provide reliable evidence. We also evaluated emerging techniques aiming at controlling brain functions situation-specifically, e.g., optogenetics and closed-loop DBS. One focus was on possible applications of PNS in forensic contexts, e.g., for treating pedophilic child offenders or psychopaths, another focus was psychosocial consequences of pediatric epilepsy surgery.

Tade Matthias Spranger (Germany):

The legal project has considered those elements of International Law, which might provide any important information regarding the legal assessment of psychiatric neurosurgery, as well as basic human rights documents (e.g., the UN Convention on the Rights of People with Disabilities, the Council of Europe’s Convention on Human Rights and Biomedicine, and the Additional Protocol to the Convention on Human Rights and Biomedicine, concerning Biomedical Research). Furthermore, the German law was examined with regard to psychiatric neurosurgery. One focus was the analysis of Ulysses contracts for psychiatric neurosurgery, another focus were issues of informed consent and free will. It was shown that so-called Ulysses testaments, which allow physicians to switch off the stimulation against the will of a legally competent patient, are no valid legal instruments.

Judy Illes (Canada):

Little is known about current public opinions, expectations, hopes, and concerns over modern psychiatric neurosurgery, particularly given the controversial history of psychosurgery. To fill this knowledge gap, the social science project investigated with support of the ethics team cross-national themes, trends and values surrounding the use of different psychiatric neurosurgery procedures. For that, they investigated how print media in Canada, USA, Germany, and Spain reported about PNS in the years 1960 to 2015. The most discussed topics and the tone of the articles were analyzed, and differences between the four countries were described. One main result was that the tone of coverage became more positive for Canada, USA and Spain over time; whereas it remained cautious in Germany. In the next step, comments made by readers in response to news articles about PNS posted between 2006 and 2017 were analyzed. For further investigating current public opinions, expectations, hopes, and concerns over PNS, a focus group study was conducted that included 8 focus groups in Vancouver, Montreal, Berlin, and Madrid. The organization of the focus groups in Madrid was supported by Roberto Martínez-Álvarez. Findings indicate that participants across all cities hold concerns about the potential impact on the authentic self of patients who undergo PNS. Furthermore, participants made many references to historical psychosurgery and mostly negative and pessimistic comments about ablative neurosurgical interventions, whereas comments to deep brain stimulation were more positive.

Roberto Martínez-Álvarez (Spain):

In the last ten years, the team of Roberto Martínez-Álvarez has operated on 120 psychiatric patients with ablative neurosurgery or with Gamma Knife radiosurgery. In this group, 68 patients had OCD, 45 patients had been treated for aggressiveness related to autism or schizophrenia oligofrenia, and seven patients for major depression. All patients have been followed up properly; the current median follow-up is 6 years. This is the largest series published in the last 20 years. The study investigated: 1) the quality of life of the patients (who had been operated and followed up for at least five years); 2) their cognitive functions pre- and postoperatively; 3) to what extent the patients and their families consider that their pre-operative expectations have been met.

Chris Bervoets (Belgium):

The psychiatric team investigated the decision-making process of patients and the experiences of patients and their primary care-givers and family members with PNS. They conducted and analyzed a total of 29 interviews with 16 OCD patients who had undergone either DBS or anterior capsulotomy, and 13 caregivers of the patients. The following themes were revealed to be important during the decision-making process of the patients: desperation, social support or pressure, expectations and fear of surgery, and financial considerations. Choosing between anterior capsulotomy and DBS was mainly determined by considering reversibility (in case of DBS) and a “quick-fix” (in case of anterior capsulotomy).

Read more about the PNS consortium and its accomplishments on NEURON's website.
For reference: Müller, S., van Oosterhout, A., Bervoets, C. et al. Concerns About Psychiatric Neurosurgery and How They Can Be Overcome: Recommendations for Responsible Research. Neuroethics 15, 6 (2022).