Lithium to Prevent Relapse after ECT: New Systematic Review and Meta-Analysis

 Out on PubMed, from researchers in Belgium and Sweden, is this systematic review and meta-analysis:

Does lithium prevent relapse following successful electroconvulsive therapy for major depression? A systematic review and meta-analysis.

Lambrichts S, Detraux J, Vansteelandt K, Nordenskjöld A, Obbels J, Schrijvers D, Sienaert P.Acta Psychiatr Scand. 2021 Jan 28. doi: 10.1111/acps.13277. Online ahead of print.PMID: 33506961

The abstract is copied below:

Objective: The risk of relapse following successful antidepressant treatment, including electroconvulsive therapy (ECT), is substantial. Lithium has been suggested to effectively prevent relapse, yet data remain limited and inconclusive. We performed a systematic review and meta-analysis to examine the efficacy of continuation treatment with lithium in preventing relapse following a successful acute course of ECT in patients with major depression, in comparison to continuation treatment without lithium. We also assessed the role of several study characteristics, possibly impacting the treatment effect.

Methods: A systematic literature search, using the PubMed, Embase, Web of Science and Cochrane Library databases (up to June 2020), was conducted for prospective and retrospective studies, including patients with unipolar or bipolar depression, that assessed the efficacy of lithium for post-ECT depressive relapse prevention.

Results: Of 2556 records screened, 14 articles reporting on 9748 participants who received continuation treatment either with (N=1571) or without lithium (N=8177) were included in the meta-analysis. Patients receiving lithium were less likely to experience depressive relapse after a successful acute course of ECT, compared to patients receiving post-ECT prophylaxis without lithium (weighted odds ratio (OR)=0.53, 95% confidence interval (CI)=0.34, 0.82), with a number needed to treat (NNT) of 7 (95% CI=4, 21). We found some limited evidence that older patients may benefit more from continuation treatment with lithium, compared to younger patients. Using the GRADE criteria, the quality of evidence for our outcome measure (i.e., relapse rate) was rated as very low.

Conclusion: Continuation treatment with lithium may have superior efficacy in reducing the risk of relapse after a successful acute ECT course for major depression, in comparison to continuation treatment without lithium. High-quality studies are needed to confirm this finding.

Keywords: Continuation Treatment; Depressive Disorder; Electroconvulsive Therapy; Lithium; Relapse.

This is an important and helpful review and meta-analysis that needed to be done. The take home message is that lithium is a useful part of post-ECT relapse-prevention strategies.

In some ways, though, the authors' task was like trying to unscramble an egg; the studies are so diverse in methodology, populations and reporting that the signal of lithium's prophylactic efficacy is muted and hidden.

We still don't know what level of lithium is needed (is it on a continuum, where some is better than none, or is there a threshold?) and what the mechanism of action is (is it the low-dose effect seen in antidepressant augmentation, or is it the classical mood episode prevention of full-dose lithium, with known standard levels?)

Despite these gaps in our knowledge (and the authors' plea for more targeted research is well taken), the clinical message is clear; it is also clear that lithium is underutilized and that the younger generation of psychiatrists is less familiar with it and more wary of prescribing it.

This paper is definitely worth a full and careful read (~25 minutes).