Perceptual learning with right unilateral versus bilateral electroconvulsive therapy

Efficacy and safety of electroconvulsive therapy in depressive disorders: a systematic review and meta-analysis

BACKGROUND

We aimed to review published work for the efficacy and safety of electroconvulsive therapy (ECT) with simulated ECT, ECT versus pharmacotherapy, and different forms of ECT for patients with depressive illness.

METHODS

We designed a systematic overview and meta-analysis of randomised controlled trials and observational studies. We obtained data from the Cochrane Collaboration Depressive Anxiety and Neurosis and Schizophrenia Group Controlled trial registers, Cochrane Controlled Trials register, Biological Abstracts, CINAHL, EMBASE, LILACS, MEDLINE, PsycINFO, and SIGLE, reference lists, and specialist textbooks. Our main outcome measures were depressive symptoms, measures of cognitive function, and mortality.

FINDINGS

Meta-analysis of data of short-term efficacy from randomised controlled trials was possible. Real ECT was significantly more effective than simulated ECT (six trials, 256 patients, standardised effect size [SES] -0.91, 95% CI -1.27 to -0.54). Treatment with ECT was significantly more effective than pharmacotherapy (18 trials, 1144 participants, SES -0.80, 95% CI -1.29 to -0.29). Bilateral ECT was more effective than unipolar ECT (22 trials, 1408 participants, SES -0.32, 95% CI -0.46 to -0.19).

INTERPRETATION

ECT is an effective short-term treatment for depression, and is probably more effective than drug therapy. Bilateral ECT is moderately more effective than unilateral ECT, and high dose ECT is more effective than low dose.

Can ECT-induced cognitive effects be altered pharmacologically?

1. A systematic review of the literature revealed twelve clinical trials that evaluated nine different drugs, and used three different conceptual models to prevent, restore or treat ECT-induced cognitive deficits. 2. This review indicated inconclusive results regarding clinical utility of any of the drugs. 3. Major factors discussed include the complexities involved in the evaluation of ECT-induced cognitive deficits, and the techniques of evaluating changes in cognitive functions. 4. Our conclusion is that future research should emphasize understanding the neural mechanisms related to ECT-induced cognitive deficits. We suggest several areas for future exploration.

Amnesia for the McCollough effect following unilateral electroconvulsive therapy: implications for laterality

The hemispheric lateralization of retrograde amnesia following unilateral electroconvulsive therapy (ECT) was measured by a novel nonverbal probe, the McCollough effect, which allowed equal and exclusive access to each hemisphere. Alternating exposure to perpendicular gratings of complementary colors (e.g., red vertical stripes alternated with green horizontal stripes) will cause subsequently presented black and white gratings to appear colored hours or even days later (the McCollough effect). Three of the patients examined (3 of 10) lost the effect in just the half visual field contralateral to the treatment side when unilateral nondominant ECT was interposed between the induction of the effect and the its test. Six patients lost the effect bilaterally following unilateral ECT. One patient retained a bilateral aftereffect. This patient had by far the shortest seizure (18 sec). Nine of 10 comparison patients, also suffering from major depression but without ECT intervening between induction and test, showed good bilateral retention of the McCollough effect. The remaining comparison patients showed no retention. These results imply that despite bilateral cortical spread of seizure activity, unilateral nondominant ECT has effects that are most pronounced over the stimulated hemisphere.

Current issues in electroconvulsive therapy

Contemporary medical and legal trends in electroconvulsive therapy (ECT) are presented. The history of ECT, underlying neurophysiological theory, recent treatment developments, potential side effects and health risks, and contrasting views between the proponents and opponents are examined. Issues involving informed consent and psychotherapy are also discussed. The analysis recognizes ECT's documented record in treating major depression but calls for further stringent research to validate its efficacy.