Electroconvulsive therapy may produce immediate relief from depression, but:

a. may result in schizophrenia.

b. can also change the hemisphericity of the brain.

c. is not a long-term improvement.

d. should not be used more than once.

I think it is c.

To determine the correct answer, let's analyze each option:

a. may result in schizophrenia.
Electroconvulsive therapy (ECT) is a treatment primarily used for severe depression, not schizophrenia. While ECT can cause side effects such as temporary confusion or memory loss, it doesn't lead to the development of schizophrenia. Therefore, option a is incorrect.

b. can also change the hemisphericity of the brain.
ECT does induce changes in brain activity, but it does not specifically alter the "hemisphericity" of the brain. The procedure primarily involves passing electric currents through the brain to intentionally trigger a controlled seizure, which can affect brain connections and neurotransmitter function. However, the notion of ECT changing the hemisphericity of the brain is not supported. Hence, option b is incorrect.

c. is not a long-term improvement.
This statement is correct. ECT can provide immediate relief for severe depression, particularly in cases where medications and other interventions have been ineffective. However, the effects of ECT are typically temporary, and maintenance treatments or other forms of therapy might be necessary to maintain long-term improvement. Therefore, option c is correct.

d. should not be used more than once.
ECT can be administered multiple times if needed, depending on the severity of the patient's condition and their response to the treatment. There is no specific guideline limiting its use to only one instance. Therefore, option d is incorrect.

In conclusion, you were correct. Option c is the correct answer.