Although the mechanisms of ECT are not completely known, the may involve

A) changes to the hormone system.
B) changes to the structure of the brain.
C) changes to patterns of sleep.
D) changes to the body's level of serotonin.

Research suggests that ECT may lead to changes in the structure of the brain, specifically the hippocampus, which is involved in memory formation and mood regulation. Although it is not fully understood how ECT brings about these changes, it is thought that the electrical current causes neurons to release certain chemicals, which in turn may promote the growth of new cells and connections in the brain. While ECT may also have effects on the hormone system, sleep patterns, and serotonin levels, these are not as well-established or central to the mechanism of action.