Neurostimulation and Mental Healthcare
Author: Shelby Prokop-Millar

Some of us may recall the famous scene from One Flew Over the Cuckoo’s Nest when we hear the term “neurostimulation”. It’s the one where Jack Nicholson’s character was shocked using electroconvulsive therapy. In this scene, his character can be seen thrashing up and down as numerous men pin him to a bed. Though it is important to recognize the potential misuse of somatic psychiatric treatments in the past, modern uses of neurostimulation are currently used safely and to great positive effect and bear no resemblance to the scene from the movie. I know this because I research neurostimulation myself.
Neurostimulation can most simply be defined as the use of electricity to alter neural activity. There are invasive (e.g., deep brain stimulation) and noninvasive (e.g., transcranial magnetic stimulation (TMS)) approaches to neurostimulation. My research specifically pertains to the noninvasive tool of deep TMS.
Various forms of neurostimulation exist (a brief breakdown of some forms of neurostimulation can be seen in Table 1) and are currently used to effectively treat a multitude of psychiatric conditions, such as major depressive disorder, schizophrenia, obsessive compulsive disorder, nicotine use disorder, bipolar disorder and more. Most often, neurostimulation is used in cases of “treatment resistance”, where patients have been unable to achieve sufficient symptom reduction with psychotropic medications and/or psychotherapy.
Table 1. Forms of Neurostimulation
Type | How Does It Work? | What Does it Treat? | Side Effects? |
Transcranial Magnetic Stimulation (TMS) | Via the utilization of a magnetic field, TMS generates a low-intensity electrical current to stimulate specified regions of the brain. There are currently three forms of TMS: (1) repetitive TMS, (2) deep TMS and (3) intermittent theta burst stimulation. | TMS has been used to treat major depressive disorder (MDD), obsessive compulsive disorder (OCD), and nicotine use disorder. | Some side effects consist of headache, neck pain, and scalp discomfort. |
Electroconvulsive Therapy (ECT) | Via the use of electrodes placed on the scalp, an electrical current is used to induce a controlled seizure. Patients are placed under anesthesia and given a muscle relaxant. | ECT has been used to treat schizophrenia, MDD, and bipolar disorder. | Some side effects consist of headache, confusion, and brief memory impairment. |
Deep Brain Stimulation (DBS) | The surgical placement of electrodes within the brain, for electrical stimulation purposes. | DBS has been used to treat Tourette syndrome and OCD. | Some side effects that can occur post-surgery include headache, seizure, confusion, and infection. Some side effects that can occur as a result of the stimulation include lightheadedness, speech issues, tingling sensation . |
Vagus Nerve Stimulation (VNS) | Electrical stimulation applied to one of the two vagus nerves, either surgically or non-surgically; surgery is required for psychiatric conditions. | VNS has been used to treat MDD. | Side effects can include throat pain, hoarseness, headache, and swallowing trouble. |

Neurostimulation has a special place at McMaster University, as Dr. Gary Hasey, an associate professor at McMaster and a psychiatrist, was the first in Canada to open a repetitive TMS clinic here in Hamilton, Ontario, in 1997. The clinic still operates to this day at St. Joseph’s West 5th Campus, with an image of Brenda, a nurse at the clinic, operating the device.
As of now, the Peter Boris Centre for Addictions Research recently began conducting clinical trials on the use of deep TMS for major depressive disorder and cannabis use disorder, under the guidance of Dr. James MacKillop, Dr. Dante Duarte (who also works at the repetitive TMS clinic) and Dr. Emily MacKillop. In fact, my thesis work is a part of the Peter Boris Centre’s first clinical trial, the DIVINE pilot trial, linked above. During this trial, we recruited 21 older adults with treatment-resistant MDD to undergo 20 minutes of deep TMS, randomized to either Hesed-coil 4 (which stimulates the anterior cingulate cortex and the medial prefrontal cortex) or 7 (which stimulates the insula, bilateral, ventrolateral and dorsolateral prefrontal cortex), once per week for four weeks. The main purpose of this pilot study was to test the tolerability and feasibility of the study protocol and stimulation, which was successful. The results of this trial should be published within the next 6 months.
Though previous renditions of neurostimulation have left a hesitancy and or a fear of such treatments within the public domain, neurostimulation has greatly evolved both in practice and in technique making it a reliable and safe approach to treating neuropsychiatric disorders. It is important for us as researchers and/or clinicians to change the narrative on neurostimulation, by educating the public on the use and safety of the procedures discussed.