ECT Methods

Let me explain a little bit about different methods of electroconvulsive therapy currently in practice. As documented in this blog, I myself received the electrode placement known as bifrontal. It is a newer application of electrodes, but the studies I have seen on it do seem promising, although we don't know as much about it since it hasn't had the time to be used long-term and has not yet experienced widespread usage. I will explain the three methods of ECT currently in practice and their differences.

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The Three Types of ECT Currently Available
Bilateral : This was the oldest electrode placement, although still practised due to its prevailing effectiveness. In this placement the electrodes are placed on the temples of the head, one on either side. During the procedure electricity travels between the two electrodes through the temporal lobes of the brain. This placement has shown to be the most effective, but also carries the highest risk of memory effects. The electricity used is about one-and-a-half times the seizure threshold, the seizure threshold being the amount of electricity required to initiate a seizure in the patient.
Unilateral: This one is newer than bilateral. In this form of ECT two electrodes are placed on the same side of the head, on the temple. This is done so that there is no electrical circuit travelling across such a large portion of the brain, and the electrical circuit is instead limited to one side of the brain. I assume this method affects the temporal lobe area as well. Although this placement is affecting a smaller portion of the brain, it is done with more electricity at a minimum of six times the seizure threshold of the individual. The cognitive and memory effects have been shown to be significantly lower than the bilateral placement, but unfortunately the overall effectiveness is lower as well.
Bifrontal: This is the most recently developed placement. During a procedure utilizing this placement the electrodes are placed on either side of the front of the forehead and the amount of electrical current used is similar to that in bilateral, being essentially just enough to cause a seizure. The point of this placement is to avoid running current through the temporal lobes all together, which are attributed substantially to memory. Indeed, so far the effectiveness of this placement seems to nearly be comparable to the bilateral placement, with a lower memory-related side effect profile. However it does utilize the frontal lobes instead, which are traditionally associated with cognition rather than memory. One has to wonder whether it may be a trade off, a matter of cognitive function being affected in place of the memory effects that are the prevalant concern from other, more studied methods. I suppose only time will tell us more as there grows further study and practice of bifrontal placement and its effects.