Investigating Relapse after ECT
Electroconvulsive therapy (ECT) is an effective treatment for patients with treatment-resistant depression, but still many patients relapse after the treatment. Medications can prolong the period of remission, but even so, relapse rates have increased in recent decades (probably at least partly because ECT was once a standard initial treatment but is now only used with those patients with the most difficult-to-treat illnesses.) A 2013 meta-analysis by Jelovac et al. in Neuropsychopharmacology reviewed existing research on relapse and which medications might be able to best prolong remission after ECT.
The researchers analyzed 32 studies that each included at least 2 years of followup. In studies from the recent era in which patients received continuation treatment with medication following ECT, 51.1% of patients relapsed within a year, and the majority of those (37.7%) relapsed within the first 6 months after ECT. Among patients treated with continuation ECT, a similar proportion (37.2%) also relapsed within 6 months of the initial ECT treatment. In randomized controlled trials, treatment with antidepressants with or without lithium following ECT halved the rate of relapse within 6 months compared to placebo.
Even with continuing intermittent ECT treatment, risk of relapse remains high, especially within the first 6 months. The authors concluded that maintenance of wellbeing following ECT must be improved.
Editor’s Note: One possibility for prolonging remission is the more intensive continuation regimen using right unilateral ultrabrief pulse ECT suggested by Nordenskjöld et al. in the Journal of ECT in 2013. Continuation treatment with a combination of ECT and medication resulted in 6-month relapse rates of 29% (compared to 54% with medication alone) and one-year relapse rates of 32% (compared to 61%).
ECT Update: Some good news and some not-so-good news
A 2013 study by Prudic et al. in the Journal of Electro-convulsive Therapy reveals some good and some not-so-good news about ECT. The good news about ECT is that it produced moderate acute remission rates. In this randomized study of ECT treatment, improvement rates were better when patients received right unilateral (RUL) ultra-brief pulse at high doses (6 times a patient’s seizure threshold) than with bilateral (BL) pulse at low doses (1.5 times the patient’s seizure threshold). RUL also has fewer cognitive side effects than BL.
Prudic also found that these acute remission rates were best when antidepressant treatment was begun at the same time as ECT rather than after the end of ECT treatment.
Unfortunately, a previous study by Prudic et al. showed that relapse rates after ECT remain high. Two-thirds of patients relapse in the first six months after ECT. Half of patients who receive antidepressant treatment following ECT relapse within the first six months after their last ECT treatment. Twenty to forty percent relapse in the first month after their last ECT treatment.
In the current study, timing and likelihood of relapse was independent of whether antidepressant treatment was started at the outset of ECT or after the end of ECT. Relapse also did not depend on which pharmacological treatments are used (nortriptyine plus lithium versus venlafaxine plus lithium).
Older patients (average age 55) did better—they relapsed less often than patients with an average age of 45. Patients with unipolar and bipolar depression did not differ in relapse rates.
Previous history of illness did affect relapse. The number of prior antidepressant trials a patient had tried for a current depressive episode (a measure of treatment resistance) was related to how fast they relapsed on follow-up pharmacotherapy after receiving ECT (more antidepressant trials was associated with faster relapse).
Other studies have shown that continuation of ECT treatment is not superior to continued treatment with drugs following ECT treatment.
Editor’s Note: ECT works acutely, but too often its effects do not last long, even with intensive continuation treatment with an antidepressant and lithium. Therefore for patients with highly recurrent illness, its usefulness is largely limited to acute emergencies, such as high risk of suicide or medical deterioration.
There are currently no good controlled studies showing how to prevent depressive relapse after remission with ECT using either drug continuation therapy or maintenance ECT. Greater degrees of treatment resistance are associated with lower rates of both acute remission and faster relapse during follow-up pharmacotherapy.
If a patient is going to have ECT, RUL would be recommended over bilateral, because bilateral ECT is associated with decreases in autobiographical memory even after six months, and these deficits are in proportion to the number of bilateral ECT treatments received.
Alternatives to ECT
Other types of brain stimulation treatments could potentially serve as alternatives to ECT. Read more
Persistence of Mild Depression Is Risk Factor for Relapse into Full-Blown Episodes
In naturalistically treated bipolar patients, depression is three times more prevalent than manic symptoms (according to studies by Judd et al., Kupka et al., and Ezquiaga et al.). The occurrence of even residual depression or subsyndromal symptoms can be highly impairing, and is a predictor of increased likelihood for subsequent relapse, according to a poster presented by Gitlin et al. at the American Psychiatric Association meeting in San Francisco in May 2009.
These new data support that of a large number of other investigators who have made similar observations, all indicating the importance of attempting to achieve full remission as a major goal of clinical therapeutics in order to decrease likelihood of relapse. Gitlin’s study further indicated that impairment of quality of life in bipolar patients was closely related to the degree of their subsyndromal symptomatology.
