Why ECT works
The exact mechanism of how electroconvulsive therapy (ECT) works is still unknown. There are multiple theories that have been put forward and research on this topic is ongoing:
The neurotransmitter theory suggests that ECT causes an alteration in the levels of various brain chemicals (called neurotransmitters) such as serotonin, norepiphrine, dopamine, and acetylcholine among others.
The anticonvulsant theory links clinical improvement to increase in the seizure threshold (amount of electricity needed to induce seizure) over time with ECT.
The neuroendocrine theory proposes that ECT causes the release of certain hormones from the hypothalamus which results in alleviation of symptoms.
Evolution of treatment
ECT works by the electrical induction of a controlled seizure. The concept of the use of intentionally-induced convulsions to treat psychiatric illnesses dates back to the 19th century.
In the early 1900’s, Ladislas Joseph von Meduna began to study the therapeutic effects of chemically-induced seizures on patients with psychosis and catatonia. These studies later lead the became the basis of Italian researchers Ugo Cerletti and Lucio Bini’s work who, in 1938, applied electricity to induce convulsions. Later studies established ECT’s effectiveness in treating major depressive disorder and other major psychiatric illnesses.
ECT was extensively used during the 1940’s and 1950’s to treat depression and psychotic illnesses. Despite continuing advances, the use of ECT waned in the 60’s and 70’s. This decline in use primarily resulted from social stigma, the advent of antidepressant and antipsychotic drugs, and a better understanding of some of the causes of psychiatric illnesses.
With significant improvements in safety and tolerability, ECT underwent a significant revival in the 1970’s. Over the past 40 years, there has been extensive refinement of the methods for electrical stimulation and ways to optimize the antidepressant effects of ECT.
Additionally, with the use of modern anesthesia, muscle relaxants, and lower charge delivery, ECT has become a mainstay of the treatment of individuals with severe, medication-refractory mood disorders and psychosis.
Today, ECT is considered among the most efficacious treatment for severe mental illnesses. Approximately 150,000 people get ECT every year in the US.