Depression is diagnosed in 14 million Americans every year, and for approximately 50% of these new diagnoses, pharmacological therapy alone does not need to cure. Electroconvulsive therapy (ECT) has been shown to be more effective than single or combination pharmacotherapy in achieving remissions of major depression; even in the elderly population, which is known to be more refractory to medication-based management, up to 50% of patients will have improvement with ECT. In addition, ECT has shown improvement in patients diagnosed with mania, schizophrenia
The practice of inducing seizure for treatment of psychiatric conditions dates back to Paracelsus in the 1500s, but ECT was first described in 1938 and for approximately 30 years, it was performed without anesthesia. Over the course of the last century, both the incidence and practice of ECT have evolved. In recent years, the number of ECT treatments performed and the methodology have changed. In recent years, the number of ECT procedures in the United States now exceeds the number of CABGs, appendectomies, and hernia repairs. An initial course of treatment will be three times a week for 6–12 treatments. Improvement, if any, is usually seen in three to five treatments. However, maintenance ECT is also necessary; this is conducted on a weekly or monthly basis, because without maintenance therapy there is a >50% relapse rate observed in the first 6–12 months. The introduction of anesthesia has also been a big change in ECT. ECT is now considered to be a low-risk procedure with a complication rate of 0.75% and mortality rates of 0.029% over the course of treatment and a 0.000045% mortality rate observed with a single treatment.
ECT is accomplished by using an electrical current creating a bilateral generalized seizure. Seizures measured on EEG to be 30 seconds in length are thought to provide optimal results, with seizures less than 15 seconds or greater than 120 seconds showing inferior outcomes. The exact mechanism by which ECT has its desired effect is unknown; however, many of the working theories revolve about discharge of neurotransmitters in the brain and body. These changes are manifested throughout the body and organ systems.
The cardiovascular effects of ECT are first observed with an initial parasympathetic discharge. This discharge lasts 5–10 seconds and manifests with hypotension and a transient bradycardia, which can progress to asystole. This is followed by a prominent sympathetic response that peaks at 1–2 minutes and can be observed for 5–10 minutes. This manifests with hypertension, tachycardia, and increased myocardial oxygen demand. On EKG, ST-segment depression, T-wave inversion, premature ventricular contractions, and rarely ventricular tachycardia can be seen, which are believed to be secondary to the sympathetic discharge.
The cerebral effects of ECT are also linked with the sympathetic discharge. Generalized motor seizures are observed in patients without neuromuscular blockade. There is also a marked increase in cerebral blood flow (100%–400%), ...