Electroconvulsive therapy (ECT) appears to fight severe depression by “pushing the reset button” on brain networks involved in creating a mental picture, according to a new study published in the journal NeuroImage: Clinical.
Since the late 1930s, psychiatrists have used ECT as part of an overall treatment plan to help people with depression who do not respond to antidepressants. During this treatment, electrical current is applied to the forehead to intentionally cause brief seizures, while the person is under anesthesia. Following a course of ECT, patients proceed with medication or talk therapy to maintain their improved condition.
“ECT has long been known to be an effective treatment for patients who don’t respond to other therapies,” said Dr. Brian Levine, senior author on the paper and senior scientist at Baycrest’s Rotman Research Institute (RRI). “But we don’t know precisely how ECT affects brain function. Our study shows how ECT alters brain networks involved in memory and thinking.”
It is well-established that people with depression tend to become focused on the negative aspects of an experience, which also blunts their memory ability. These individuals have difficulty reframing their thoughts toward healthier interpretations of past events.
“Since people with depression struggle to reframe an event, their ability to cope with adverse situations is affected,” says Dr. Raluca Petrican, co-first author on the paper and RRI postdoctoral fellow. “Our study suggests that ECT reconfigures brain networks that promote flexibility in how people remember events, and this may help people cope better with daily challenges.”
For the study, the research team looked at the brain scans of 25 adults between the ages of 25 to 60 years old. Among the participants, 15 individuals were severely depressed and referred for electroconvulsive therapy at psychiatric clinics across Toronto.
All participants were asked to share some notable events with researchers at the beginning of the study. They were then cued to imagine these events while they were inside the scanner.
Those who were recommended for ECT did scans before and after all their sessions. The results show that before ECT, the brain networks linked to visualization appeared to function differently among individuals with depression, but after ECT, these brain networks looked similar to healthy individuals.
The findings were validated in a publicly available database of more than 300 individuals who had their brains scanned as part of a separate study but did not have ECT. Based on these scans and access to the database, researchers were also able to link a person’s brain networks to their resiliency or susceptibility to depression.
As next steps, the researchers will be investigating the amount and types of memory loss experienced by patients who undergo this treatment, as this is a common side effect of ECT.