I was about to start a thread to ask this but found this sticky thread. It helps a lot! The interrupting tag is what I was looking for. I just have to ignore my MS Word complaints:
"The main reason behind this," he explained. "is the fact that he is in his manic state."
Word wants to cap the next quoted statement, then add a question mark because it starts with "Is".
You put a period where a comma should be after "explained".
"The main reason behind this," he explained, "is the fact that he is in his manic state."
See the opening post.
Tag interrupting a dialog sentence:
"That," he said, "is fine. Whatever you decide."
"That, "he said, "is fine. What does she think?"