Short answer
Electroshock therapy is a very effective and safe treatment for a number of psychiatric disorders. With this therapy, small electric shocks are given to the brain, which generate something that resembles an epileptic seizure. This technique has existed for almost a hundred years and is used worldwide, including in the Netherlands, in order to treat people with severe depression. The effects of electroshock therapy on the brain are difficult to quantify, but are getting clearer every year.
Longer answer
It is possible that the notion of electroshock therapy brings up gruesome images of Jack Nicholson in the blockbuster “One Flew Over the Cuckoo’s Nest”. Playing the role of ‘Randle’, who ends up locked up in a psychiatric institution, he is declared insane, tied up, and treated with electroshock therapy against his will, and thus ends the movie. The final ‘medicine’ to try and subdue him and his spirit seems to have finally worked!
This and other dramatic interpretations of electroshock therapy contain strong fictional elements that do not comply at all with the appropriate use of this everyday practice. Electroshock therapy used in clinics is usually called electroconvulsive therapy (ECT). ECT is used as a last remedy for cases such as severe depression and schizophrenia. Psychiatric patients receive ECT in the two following cases: (1) when neither cognitive therapy (sessions with a psychologist) nor medicine such as antidepressants (to treat depression) or clozapine (to treat schizophrenia) seem to work or (2) in rare cases where people pose a danger to themselves or others.
Far from the scenes of fictional Randle stuck in a psychiatric institution, most people in question live at home. They come in for treatments twice a week at one of the thirty clinics in the Netherlands that offer ECT sessions. These sessions are short: the treatment itself takes about 20 seconds, where short electric shocks of about 1 ampere (the strength of a bicycle light) are administered via electrodes stuck to the head. In the Netherlands, patients are always sedated and given muscle relaxants, so that no muscle convulsions (cramps and shocks throughout the body) occur. Furthermore, a slew of measuring equipment (including an electrocardiogram (ECG) to measure the heart activity) and a crew of medical professionals (including an anaesthesiologist to oversee the sedation) see to it that all proceeds safely. After about twelve sessions (spread out over six weeks), the treatment is completed.
While ECT is safe, there are some known side-effects. It does occur that patients have memory complaints. It is possible that, during treatment, the episodic memory is affected: people struggle to recall their (recent) 40th birthday or their wedding. Some memories return after the ECT sessions, and some memories are never affected. It is not the case that people forget how to brew a cup of coffee. It is possible that people struggle find their words, coming right out of an ECT session, because the speech node in the brain is affected (stimulation from the right side may prevent this, because almost everyone’s speech node is in their left hemisphere). It is not yet fully understood how much of these side-effects are caused by the ECT itself and how much are due to the temporary sedation that patients receive during these treatments (to prevent convulsions).
Despite the safety and efficiency of this technique, ECT still has its ‘bad rep’. But the 1-2 % patients that qualify for this treatment do choose to receive this treatment. A more popular approach is the recent (re-)discovery of ketamine when treating depression, and some patients even prefer deep brain stimulation (an effective, but also more invasive treatment where electrodes are placed into the brain). All this, in spite of the fact that ECT has been around for almost a hundred years and shows promising results in over 50% of patients. This percentage might not seem high, but we are talking about a group of patients that do not respond to prior therapy or medication.
Upper: The original machine, by Ugo Cerletti and Lucio Bini, used for the first ever ECT treatment in humans. The machine stands in the Museo di Storia della Medicina (Museum of Medical History) of the Sapienza University in Rome. [image from Alessandro Aruta, Museum Curator – Sapienza University]. Lower: An example of a modern ECT machine, where precise amperage and frequency can be calibrated by medical professionals.
[https://nl.wikipedia.org/wiki/Elektroconvulsietherapie].
The invention of the ECT goes back to the early 30s of the last century and is mostly based on the work of an Italian neurology duo. Ugo Cerletti and Lucio Bini were observing how pigs received an electric shock before they were slaughtered and it calmed them down. After extensive animal research in order to optimize the parameters for the ECT, they developed their first, safe machine in order to treat humans, and quickly already noted positive effects after 10-20 sessions. The technique has been adapted over the years (for instance, the inclusion of sedation and muscle relaxants) and, at this moment, a million people are being treated with ECT every year, worldwide.
Animal studies are still being used. But now, in order to better understand what ECT does to the brain. With severe depression, brain cells die and connections between cells diminish; this affects the network in our brain. In animals (in this case, mice and rats are often used), these connections are reformed after ECT and there are even new neurons formed (in a process we call neurogenesis). It is harder to research this in humans, and to research what the effects of ECT are on the human brain. When researchers compare the brain scans (MRIs) of patients before and after treatment, they see a subtle growth in brain areas such as the hippocampus (4-5% growth) and the amygdala (5-6% growth). What this growth suggests, and whether it corroborates either the results of the animal studies on a cellular level, or the positive results noted in patient groups, is still being researched at the moment.
When you compare patient MRI scans from before and after ECT, there are a number of brain areas where the grey matter (neurons) volume has increased. The image above shows a summary of a large number of studies researching the increase in grey matter. Growth is mostly seen in the Hippocampus (HIP) and the Amygdala (AMY). Other areas such as the Putamen (PUT), the Cingulate Gyrus (CNG) and the Parietal, Frontal and Temporal Lobes (PL, FL and TL) show less growth. This image is sourced from an article by Ousdal and colleagues: [10.1016/j.biopsych.2021.05.023].
In clinics worldwide, electroshock therapy, or ECT, is not only used; it is being improved upon. ECT remains one of the most effective and safe treatments for severe depression and schizophrenia. Unfortunately, this method has (unjustly) gained a bad reputation which, in time, can be detrimental to people who could greatly benefit from this treatment. The ‘Randle’, in real life, is much less sensational. He is not locked up against his will, stuck in a psychiatric ward with tormentors. He (or she), drives to the clinic once or twice a week for a voluntary, short treatment to rid himself (or herself) of the tormentors in his (or her) head.
Further reading material:
Ousdal, O. T., Brancati, G. E., Kessler, U., Erchinger, V., Dale, A. M., Abbott, C., & Oltedal, L. (2022). The neurobiological effects of electroconvulsive therapy studied through magnetic resonance: what have we learned, and where do we go? Biological psychiatry, 91, 540-549.
Scheepens, D. S., van Waarde, J. A., Lok, A., de Vries, G., & van Wingen, G. A. (2020). The link between structural and functional brain abnormalities in depression: A systematic review of multimodal neuroimaging studies. Frontiers in psychiatry, 11, 486702.