In comparing ECT patients with patients receiving a placebo, it has been found that those who receive ECT display greater reduction in symptoms scores that those treated with a placebo. In a review of some of the studies comparing ECT with anti-depressant drugs, it was found that ECT was more effective than antidepressants. However, problem with many of the early studies is that they were methologically flawed.
In cases where ECT was compared with simulated ECT, double blind procedures were not employed, which meant that the patient assessor knew who had, and who had not, received ECT, allowing for possible bias in assessment, and thus, results. In response to criticism about early investigations into the efficacy of ECT, more recent studies have adopted more rigorous methodologies to safeguard against experimenter bias. [1] In a double blind trial to compare the effectiveness of bilateral ECT with simulated ECT, it was found that genuine ECT was significantly superior to simulated ECT in the treatment of bi-polar disorder.
ECT is clearly superior to simulated ECT, there is also evidence that, in the long run, simulated ECT does equally well. Similar studies have found bi-polar disorder to be significantly reduced in patients receiving bilateral ECT compared with patients receiving simulated ECT. The side-effects of ECT are small and short lived, however other researchers claim that they are serious and long-term. [4] A foremost fear concerning ECT as a treatment alternative is usually not whether it is efficient but whether it is related with long-term cognitive issues, mainly in different memory systems.
Conceivably the main contentious problem is whether ECT results in long-term (usually defined as greater than 6 months) changes in antero-grade or retrospective memory performance; this is also a problem of clinical relevance. Current researches of people undergoing ECT method treatment perception of memory loss after ECT are remarkable. A number of researchers summarized the results of some studies reporting on perceived memory loss and found that between 29% and 55% of respondents believed they experienced long-lasting or permanent memory changes.
Complaints persist long after ECT treatment. [3-4] Our understanding of the cognitive effects of ECT is largely confined to studies of patients with uni-polar depression. There are, still, substantial differences between bi-polar disorder and uni-polar depression on several cognitive dimensions. Several, although not all, studies suggest that people with bi-polar disorder are generally more likely to have cognitive deficits when euthymic than are people with uni-polar depression.
It is not known whether the cognitive changes in bi-polar disorder are patho-physiologically distinct from the cognitive changes in uni-polar depression. Further, memory is not a unitary construct, and it is possible that discrete memory systems could be differentially affected by ECT and other forms of treatment. [5] Thus extrapolating from studies of uni-polar depression is not a reliable way to make conclusions regarding the impact of ECT on memory for people with bi-polar disorder.