Table 1.

Legislative definitions of NPD.

Jurisdiction	Technique	Included indications	Excluded indications	Legal citation
Pacific
New Zealand	“Brain surgery” Any surgery or other treatment intended to destroy any part of the brain or brain function	For mental disorder	N/A	Mental Health (Compulsory Assessment Treatment) Act, 1992 Sections 61, 88
South Australia	“Neurosurgery for mental illness” Leucotomy, amygdaloidotomy, hypothalamotomy, temporal lobectomy,a cingulotomy,b electrode implantation in the brain or any other brain surgery for treatment of mental illness by the elimination or stimulation of apparently normal brain tissue	For mental illness	N/A	Mental Health Act, 2009 Sections 3, 43
Victoria (Australia)	“Neurosurgery for mental illness” (a) any surgical technique or procedure by which one or more lesions are created in a person's brain on the same or on separate occasions for the purpose of treatment; or (b) the use of intracerebral electrodes to create one or more lesions in a person's brain on the same or on separate occasions for the purpose of treatment; or (c) the use of intracerebral electrodes to cause stimulation through the electrodes on the same or on separate occasions without creating a lesion in the person's brain for the purpose of treatment	For the purpose of treatment “treatment” is defined as including steps to remedy a person's mental illness or to alleviate the symptoms and reduce the ill effects of a person's mental illness “treatment” is defined to include neurosurgery for mental illness.	N/A	Mental Health Act, 2014a Sections 3, 6
New South Wales (Australia)	“Psychosurgery” (a) the creation of 1 or more lesions, whether made on the same or separate occasions, in the brain of a person by any surgical technique or procedure, (b) the use of electrodes within the brain to produce such a lesion or lesions, whether on the same or separate occasions, or (c) the use on 1 or more occasions of electrodes within the brain primarily for the purpose of influencing or altering the thoughts, emotions or behavior of a person by stimulation through the electrodes without the production of a lesion in the brain of the person	Primarily for the purpose of influencing or altering thoughts, emotions or behavior	Does not include a technique or procedure carried out for the treatment of a condition or an illness prescribed by the regulations for the purposes of this definition. The regulation specifies that “psychosurgery” does not include neurological procedures carried out for the relief of symptoms of Parkinson's disease, Gilles de la Tourette syndrome, chronic tic disorder, tremor, dystonia and epilepsy.	Mental Health Act, 2007 Section 83 Mental Health Regulation, 2019 Section 11
Australian Capital Territory	“Psychiatric surgery” Specialized neurosurgery for psychiatric conditions “Neurosurgery” Surgery on the brain of a person for treating a pathological condition of the physical structure of the brainc	For psychiatric conditions	N/A	Mental Health Act, 2015 A2015-38 Section 145
Queensland (Australia)	“Psychosurgery” A procedure on the brain, that involves deliberate damage to or removal of brain tissue, for the treatment of a mental illness. “Non-ablative neurosurgical procedure” A procedure on the brain, that does not involve deliberate	For the treatment of a mental illness	For the purpose of non-ablative neurosurgery, certain conditions do not constitute mental illness: chronic tic, dystonia, epilepsy, Tourette, Parkinson's, tremor, another neurological disorder prescribed by regulation damage to or removal of brain tissue, for the treatment of a mental illness.	Mental Health Act, 2016 Section 9, 10, Schedule 3 Mental Health Regulation, 2017 No provisions in this regulation mention psychosurgery or non-ablative neurosurgical procedures.
Fiji	“Psychosurgery” (a) The creation of one or more lesions, whether made on the same or separate occasions, in the brain of a person by any surgical technique or procedure, when it is done primarily for the purpose of altering the thoughts, emotions or behavior of the person; (b) the use for such a purpose of intracerebral electrodes to produce such a lesion or lesions, whether on the same or separate occasions; or (c) the use on one or more occasions of intracerebral electrodes primarily for the purpose of influencing or altering the thoughts, emotions or behavior of a person by stimulation through the electrodes without the production of a lesion in the brain of the person	Primarily for the purpose of altering the thoughts, emotions or behavior of the person;	Does not include a technique or procedure carried out for the treatment of a condition or illness prescribed for the purposes of this definition.	Mental Health Act, 2010 Section 52
Asia
Indiad	“Psychosurgery” No interventions specified.	For mental illness	N/A	Mental Healthcare Act, 2017 Section 96
Europe
United Kingdome	“Any surgical operation for destroying brain tissue or for destroying the functioning of brain tissue” and other forms of treatment specified by regulation The additional treatment specified in the Regulation is not relevant here (implantation of hormones to reduce male sexual drive).	For mental disorder	N/A	Mental Health Act, 1983 1983 c.20 Section 57 Mental Health (Hospital, Guardianship and Treatment) (England) Regulations, 2008, 2008 No. 1184 Section 27
Scotland	The law sets out rules for “medical treatment” falling within the definition of “certain surgical operations”: any surgical operation for destroying— brain tissue; or the functioning of brain tissue; and such other types of medical treatment as may be specified in regulations for the purposes of this Section. The regulation specifies “deep brain stimulation” which is defined as “the focal modulation of the activity of specific brain regions by direct electrical stimulation delivered by electrodes which are stereotactically implanted in the brain and attached to a programmable control unit inserted in the chest which delivers electrical stimuli. administered repeatedly, over an extended period.” f The act also specifies special rules for electro-convulsive therapy and “such other types of medical treatment as may be specified in the regulations” (section 237) The regulation goes on to specify transcranial magnetic stimulation and vagus nerve stimulation. These are defined as follows: “Transcranial magnetic stimulation” means the focal modulation of the activity of specific brain regions, by the administration of a changing magnetic field repeatedly, over an extended period “Vagus nerve stimulation” means the intermittent electrical stimulation of the cervical portion of the left vagus nerve by a surgically implanted, programmable electronic device which administers electrical stimuli repeatedly, over an extended period.	“Medical treatment” means “treatment for mental disorder”	N/A	Mental Health (Care Treatment) (Scotland) Act, 2003 Section 234, 329 Mental Health (Medical treatment subject to safeguards) (Section 234) (Scotland) Regulations, 2005 Mental Health (Medical treatment subject to safeguards) (Section 237) (Scotland) Regulations, 2005
Ireland	“Psycho-surgery” Any surgical operation that destroys brain tissue or the functioning of brain tissue	For the purposes of ameliorating a mental disorder.	N/A	Mental Health Act, 2001 2001 No. 25. Sections 58.
Portugal	“Intervenção psicocirúrgica” Translation: psychosurgical intervention No further definition given in the statute.	N/A	N/A	Lei de Saúde Mental Lei No. 36/98 Art 5
South America
Brazil	“A neuropsicocirurgia e quaisquer tratamentos invasivos e irreversíveis para doenças mentais” Translation: neuropsychosurgery and any invasive and irreversible treatments for mental illness No further definition given in the Resolution.	Para doenças mentais Translation: for mental illnesses	N/A	Resolução and no. 2.057/2013 Art 19, 20.
Chile	“Psicocirugía o cirugía aplicada al tejido cerebral” Translation: psychosurgery or surgery applied to brain tissue No further definition provided in these documents.	con el fin de suprimir o modificar funcionamientos o conductas del paciente Translation: in order to suppress or modify patient functioning or behavior	N/A	Ley Numero 20.584, Regula los derechos y deberes que tienen las personas en relación con acciones vinculadas a su atención en salud. 2012 Art. 24 Chile, 1998 Art. 25 Chile, 2002
North America
Alberta (Canada)	“psychosurgery” Any procedure that, by direct or indirect access to the brain, removes, destroys or interrupts the continuity of histologically normal brain tissue, or that inserts indwelling electrodes for pulsed electric stimulation	For the purpose of altering behavior or treating psychiatric illness	But does not include neurological procedures used to diagnose or treat intractable physical pain or epilepsy where those conditions are clearly demonstrable	Mental Health Act, 2000, c M-13 s. 1
Saskatchawan (Canada)	“Psychosurgery” Any procedure that by direct access to the brain removes, destroys or interrupts the normal connections of the brain for the primary purpose of treating a mental disorder or involves the implantation of electrodesh	For the primary purpose of treating a mental disorder	But does not include neurosurgical procedures designed to treat reliably diagnosed organic brain conditions or epilepsy	Mental Health Services Act, S.S., 1984-85-86, c M-13.1 s. 2.
Texas (USA)	“Psychosurgery” A surgical intervention to sever nerve fibers connecting one part of the brain with another, or to remove or destroy brain tissue	With the intent of modifying or altering severe disturbances of behavior, thought content or mood	Surgery for the relief of intractable physical pain or to treat neurological disease or abnormality	25 Texas Administrative Code §405.103(15), 1993
California (USAi)	“Psychosurgery” Those operations currently referred to as lobotomy, psychiatric surgery, and behavioral surgery and all other forms of brain surgery”	For the purpose of any of the following: (1) Modification or control of thoughts, feelings, actions, or behavior rather than the treatment of a known and diagnosed physical disease of the brain. (2) Modification of normal brain function or normal brain tissue in order to control thoughts, feelings, actions, or behavior. (3) Treatment of abnormal brain function or abnormal brain tissue in order to modify thoughts, feelings, actions or behavior when the abnormality is not an established cause for those thoughts, feelings, actions, or behavior.	Psychosurgery does not include “prefrontal sonic treatment” wherein there is no destruction of brain tissue.	California Welfare and Institutions Code § 5325(g) (introduced in the Lanterman-Petris-Short Act, 1967)
Missouri (USA)	“Psychosurgery” (a) Surgery on the normal brain tissue of an individual not suffering from physical disease for the purpose of changing or controlling behavior; (b) surgery on diseased brain tissue of an individual if the sole object of the surgery is to control, change or affect behavioral disturbances, except seizure disorders	In the case of normal brain tissue–for the purpose of changing or controlling behavior. In the case of diseased brain tissue—where the sole purpose is to control, change or affect behavioral disturbances.	In the case of diseased brain tissue, an exception is made for seizure disorders.	Revised Statutes of Missouri 630.005(27)
Utah (USA)	“Psychosurgery” A neurosurgical intervention to modify the brain	To reduce the symptoms of a severely ill psychiatric patient.	N/A	Utah Administrative Code R523-8-5(1)(c), 2015
Oregon (USA)	“Psychosurgery” Any operation designed to produce an irreversible lesion or destroy brain tissue	For the primary purpose of altering the thoughts, emotions or behavior of a human being.	Does not include procedures which may produce an irreversible lesion or destroy brain tissues when undertaken to cure well-defined disease states such as brain tumor, epileptic foci and certain chronic pain syndromes	Oregon Revised Statutes § 677.190

^aA potential ambiguity in the drafting of South Australia's law is that “temporal lobectomy” is used for treatment of epilepsy (Wiebe et al., 2001; Franzini et al., 2019). Its inclusion in the definition of the phrase “neurosurgery for mental illness” suggests that the law means it be included only when it is performed for mental illness, and not epilepsy, which is not today classified as a mental illness. However, any uncertainty in whether to classify a condition as a mental illness or not would create uncertainty about the scope of the law. For greater clarity, some of the other laws explicitly exclude interventions like epilepsy or pain.

^bThe statute actually uses the term “cingulectomy” and not cingulotomy.

^cNote a possible legal drafting error in this definition. The legal definition of neurosurgery appears to restrict the meaning of neurosurgery to interventions to situations in which physical pathologies are known. This would appear to restrict the meaning of “psychiatric surgery,” which incorporates the term. This is unlikely to be the intended interpretation of the law.

^dSee also the discussion of this law in Doshi et al. (2019).

^eThe UK Mental Health Act is presently being revised.

^fNote that DBS programmable control units are not always implanted in the chest (e.g., Garg et al., 2010), revealing the peril of overly precise legislative drafting.

^gIn Brazil, the federal Lei 3268/1957 delegates to the Conselho Federal de Medicina (CFM), a self-regulatory body, the authority to regulate the professional practice of physicians and surgeons. The CFM Resolutions govern the practice of medicine in Brazil and have a binding effect for health care professionals.

^hNote that there is a potential drafting error. The phrase “for the primary purpose of…” appears to qualify lesional interventions but not the implantation of electrodes. This would have the unusual effect of meaning that the implantation of an electrode would fall within the definition whether or not its primary purpose was to treat a mental disorder, whereas lesional interventions would fit within the definition only when the primary purpose was to do so.

ⁱNote that California has three slightly different definitions of psychosurgery occurring in five different legislative provisions: Cal. Welf. & Inst. Code § 4503; 17 CCR § 50510; 22 CCR § 76525, Cal.Welf. & Inst.Code § 5325(g), 9 CCR § 836. Only one of these is definitions is presented here.