ECT halves suicide percentage in first year after hospitalization for depression

Toronto: Electroconvulsive therapy (ECT) was associated with a 50 per cent reduction in risk for suicide among patients with depression in the year after their hospitalizations, according to a new CAMH- and ICES-led study of over 67,000 patients published in the journal The Lancet Psychiatry.

It is the most convincing study to date that establishes a clear link between ECT and suicide prevention, and builds on a previous CAMH study using ICES patient data published in The Lancet Psychiatry in July 2021 that established that ECT has a very safe medical side effect profile.

"ECT significantly reduced the risk of suicide death while also being a medically safe procedure," said lead author Dr. Tyler Kaster, Medical Head of the Temerty Centre for Therapeutic Brain Intervention at CAMH. "These findings suggest that ECT can prevent suicide in severe depression and potentially be a life-saving procedure."

Researchers have been challenged with finding answers to the important question of how to measure the impact of ECT on suicide prevention, since to study this in a clinical trial would be next to impossible. Suicide is an extremely rare event, so tens of thousands of patients would need to be enrolled in such a trial. This study used ten years of Ontario patient hospitalization data housed at ICES, including the Ontario Mental Health Reporting System that provides an unprecedented level of detail regarding the social, demographic and clinical characteristics of patients hospitalized for mental health problems in Ontario. These datasets enabled the researchers to identify patients with depression who received ECT as well as patients with very similar characteristics who did not receive ECT – and then look forward to compare the two groups on their risk for suicide in the year after hospitalization.

Among the 67,000 patients hospitalized for depression during the ten-year study period, just under 9 per cent received ECT while the other 91 per cent did not. According to the authors, the reasons patients do not receive ECT is fear about the procedure, lack of access to treatment, or ECT not being presented as an option by the clinical team.

"I think within our own healthcare system in Ontario, the rest of Canada and globally, this study should reinforce the importance of ensuring access to ECT for inpatients admitted with severe depression because it can save lives," said study corresponding author Dr. Daniel Blumberger, Director of the Temerty Centre and Co-Chief of the General Adult Psychiatry and Health Systems Division at CAMH. "But during the pandemic, in part because of the backlog of cancelled surgeries, access to ECT has been reduced. One of the important messages of this study is that we need to ensure there is access to ECT for all patients hospitalized with severe depression."

Over the study period, patients who received ECT had 50 per cent fewer suicides in the year after their hospitalization than those who did not receive ECT and death from any cause in the first year after hospital release was reduced 25 per cent.

The authors state that the primary purpose of the study was to determine the benefits of ECT with respect to suicide, so that clinicians and patients could better understand the value of the treatment.

"Providers and patients express much uncertainty about whether to undertake a course of ECT treatment," said Dr. Simone Vigod, study co-author, senior adjunct scientist at ICES and Head of the Department of Psychiatry at Women's College Hospital in Toronto. "Some of this relates to misconceptions about what ECT is, and when it should be used. Some of it relates to ongoing uncertainty about the potential benefits and risks. We wanted to generate data that is useful for patients and providers in decision-making about ECT. Combined with the previous work on its medical safety, the current work showing that people with severe depression who receive ECT are at substantially lower risk for suicide over the year following discharge than similar people with severe depression who do not receive ECT should provide quite a bit of reassurance for patients and providers. We hope physicians will take notice and consider this evidence with their patients that have severe depression."

Shelley Roberts was one patient with treatment-resistant depression who chose ECT. As a young mother she was worried about the potential memory loss associated with ECT, but in the end felt that she had to do it.

"I didn't want to lose any memories of my son growing up, but I was afraid that if I didn't do anything he wouldn't have a mother anymore," said Roberts. "I wouldn't be alive today if not for ECT."

In Canada, over 1 in 9 adults (3.2 million Canadians or 11.3 per cent) will experience major depression in their lifetime, at which time they will most likely be prescribed antidepressants and/or psychotherapy. However, about a third of these individuals will fail to respond to these first-line treatments, and then will be diagnosed with treatment-resistant depression. There are a number of interventions for this condition including medication combinations, new drugs like ketamine and a neurostimulation treatment called repetitive transcranial magnetic stimulation (rTMS). However, when these treatments don't lead to improvement or when a depression becomes very severe leading to hospitalization, ECT is often considered as the next step, as it is highly effective at rapidly reducing symptoms of depression and suicidal thinking. Learn more about ECT.

CAMH's Temerty Centre for Therapeutic Brain Intervention is one of the world's leading centres in brain stimulation treatment, research and training. Through clinical research projects, the Temerty Centre is driving treatment advances using repetitive transcranial magnetic stimulation (rTMS), magnetic seizure therapy (MST), and ECT.

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10.1016/S2215-0366(22)00077-3