Kristin Wall
Mar 23, 2012

Unlocking how electroconvulsive therapy works is changing our understanding of depression

Images showing a substantial reduction in functional connectivity after ECT.Electroconvulsive therapy (ECT) was introduced in the 1930s as a psychiatric treatment for patients suffering from severe depression.  Because this method involves electrically inducing seizures in anesthetized patients, and may sometimes be accompanied by (usually) temporary memory-loss, it can seem risky to many. Though this treatment was highly controversial, it proved effective in helping patients that had been unresponsive to other treatment measures to overcome their mental illnesses. In fact, seventy-five to eighty-five percent of patients who undergo ECT recover from their depression symptoms. This procedure has continued to be utilized over the subsequent seventy years, despite a lack of understanding of the underlying mechanism. 

Researchers at Aberdeen University, however, believe they have discovered the basis for this treatment’s efficacy. Through use of functional magnetic resonance imaging (fMRI) and complex mathematical analysis, these scientists were able to pinpoint how the twenty-five thousand different areas of the brain communicate.  The studies revealed that ECT appears to 'turn down' an overactive connection between areas of the brain that control mood and the portions responsible for thinking and concentrating. This decrease in connectivity observed after the treatment was accompanied by a significant improvement in patients’ depressive symptoms.

Current depression treatments, such as psychotherapy and anti-depressants, don’t address this hyperconnectivity, but rather focus on the subsequent symptoms stemming from this connectivity. This study, therefore, may lead to new drug therapies that target hyperconnectivity as ECT does, while avoiding memory-loss side effects inherent in the shock therapy. In fact, scientists have discovered that psilocybin, the active ingredient in the psychedelic drug known as magic mushrooms, disrupts this hyperconnectivity targeted by ECT. The methods of analysis utilized in the ECT study could also find applications in other psychological disorders, including schizophrenia, autism or dementia.

Researchers now hope to monitor patients to observe the long-term effects of ECT procedures, and to determine whether the hyperconnectivity returns over time. If the decreased connectivity is short-lived, patients may be hesitant to undergo regular sessions of electric shock therapy, especially with the risk of memory loss. However, if the connectivity remains decreased in the long term, ECT and future developed drug treatments targeting hyperconnectivity could be viable options for treating patients with severe depression or other mental illnesses.