Conclusions in Gryglewski et al may not be warranted

A number of issues not addressed in Gryglewski et al require comment and clarification.¹ First, the authors show that a significant increase in volumes in amygdala nuclei, hippocampus, putamen and cortical thickness occurred following a course of electroconvulsive therapy (ECT) in 12 patients. However, it is not stated whether these patients’ brain structures average size at baseline is significantly different to what we would expect to find in a healthy cohort, or what percentage of the sample fall below the norm. If this is not clarified, we need to understand why brain structure sizes that may fall within a normal distribution would require enlarging.

Second, patients had two scans before ECT and the authors present the average of the two scans as baseline measures. The authors omit to say how different the measurements were between the two pre-ECT scans, which would inform the reader as to the accuracy of each magnetic resonance imaging reading. This is important since the same procedure was not employed at termination of treatment.

Third, the authors attribute the increase in volume to a process of neurogenesis, which they consider a positive outcome. However, they do not seem to take into account the possibility that the neurogenesis may not be benign but be the result of the electrical insult inflicted on the brain, and that the proliferation and morphology of the newly created neurons may not be normal. Neurogenesis has also been observed to occur in similar areas of the brain following intake of lithium and other mood stabilisers, but it was found that the number and morphology of the cells were abnormal, with ‘increasing growth of cone formation, leading to the spreading of the neuron and a shorter neuronal axon’.² If such cellular proliferation in the areas connected with memory is a positive outcome, rather than a pathological reaction to a brain insult, then widespread memory and cognitive impairment found in a large percentage of patients who have had ECT³ needs explaining.

Fourth, and related to the last point, there is no data presented on the incidence of adverse effects following ECT (disorientation, confusion, memory loss, concentration, impairment in abstract reasoning, overall level of cognitive functioning, docility, lethargy and apathy), which may impact on the ability to perform a post-treatment test.

Finally, the authors bemoan the difficulty with recruiting ‘suitable patients’ and ended up with a very small sample. In an era of antidepressant-induced treatment-resistant depression,^4,5 I suspect that a fairly large number of patients in the University Clinic of Vienna would have met inclusion criteria. It is possible that other patients-related factors may have been involved in accounting for the very low sample size. In this respect, a wide gap between mainstream psychiatrists’ views and patients’ views regarding the usefulness of ECT has been revealed in a systematic review.⁶