I see this treatment prescribed to patients with a wide range of difficulties, though persistent depression is the most common. I have seen it cause very remarkable shifts in people's attitude or behavior, and I've also seen people do a lot of them and then return to the hospital sometime later and restart another series. The basic thing with ECT is that it seems to need frequent renewal, and some people will get them consistently for a long period of time. As noted above, there are concerns that this can cause problems with memory, though the short term effects are fairly negligible.

It's definitely something to discuss with a doctor/therapist. Just like with any medication, it's going to affect everyone in a particular way.