Sen. John Walsh (D-Mont.) on Friday walked back his previous comments in which he appeared to blame Post Traumatic Stress Disorder for plagiarism that was recently discovered when he was at the U.S. Army War College.

The New York Times reported Wednesday that the paper Walsh wrote while at the Army War College includes several passages from academic papers and other sources.

Sen. John Walsh, D-Mont., right, said Friday that he should not have blamed his plagiarism on PTSD. (AP Photo/Lauren Victoria Burke, File)

On Thursday, Walsh said PTSD may have contributed to that error.

“I don’t want to blame my mistake on PTSD, but I do want to say it may have been a factor,” Walsh said to the Associated Press. “My head was not in a place very conducive to a classroom and an academic environment.”

In a Friday radio interview, Walsh said he shouldn’t have said PTSD was a factor.

“I am in no way, no way, tying… what I did to any type of… PTSD,” he said. “That had nothing to do with the mistake that I made. People are trying to say I may have said that. If that was the, you know, thought of that, that’s not at all in any way what I meant or said.”

Walsh also said he had dozens of other citations in his report, but admitted he “cited some of them incorrectly, and I left some of the citations off.”

“It was an unintentional mistake, and that’s all I can say about it.”

Walsh was appointed to the Senate to fill the seat formerly held by Max Baucus, who was confirmed to be the U.S. ambassador to China. Walsh is running for the seat, and in a poll released this week, Walsh trailed Rep. Steve Daines 45-41.