HILLSBORO, Ore. — U.S. Rep. David Wu tried Monday to reassure constituents following reports about his odd behavior on the campaign trail and concerns over his mental health.

Wu took questions from a largely sympathetic audience at the Washington County Democratic Central Committee, four months after an angry address to the group prompted a complaint from a Democratic activist and fueled concerns among staff that Wu needed psychiatric care. Seven staff members resigned following Wu's re-election in November.

The seventh-term Democrat from Portland thanked the group of party activists for hard work that he said helped secure his win last year and helped boost Democratic Gov. John Kitzhaber to a narrow victory.

He listened praise of his courage to speak publicly and was greeted with two standing ovations.

But he also fielded questions from weary voters. Michael Crabbe, of Beaverton, wanted to know how Wu planned to talk with voters about his health following more than two weeks of reports about his inappropriate behavior.

"You're answering the bell for us tonight," Crabbe told Wu. "I need to hear from you how you're going to answer the bell from the voters in District 1."

Wu responded that he's reached out through the media and plans to continue holding meetings in his district to talk face-to-face with constituents.

Robert Seward, a retired physician from Forest Grove, wanted to know specifics about Wu's mental and physical health and the treatment he's received.

"This whole issue is your fitness to command, your fitness to be our congressman," Seward said. "The burden of proof is on you to show us that you've had an evaluation and you're fit."

Wu said he's had a physical since the election and that Wright would be impressed with his doctor's reports.

Crabbe and Seward both said afterward that they felt more comfortable that Wu was capable of serving them in Congress, but Seward would still like to know more specifics about Wu's last psychiatric evaluation.

"I feel a lot better about him than I did before," Seward said. "He's going to the voters. That takes courage. That takes openness."

But Dennis Rychlik, of Hillsboro, was less convinced. He felt Wu was more careful about hiding details than he was about revealing them. He wants to know when Wu last had a mental health exam and the precise reasons his staffers resigned.

"This didn't settle anything for me," Rychlik said.

Earlier in the day, Wu spoke briefly at the Washington County Public Affairs Forum in Hillsboro. He told about 50 people that he's capable of doing his job and took responsibility for his "inappropriate" behavior.

"I am very capable of taking care of my constituents here in Oregon, very capable of discharging the obligations that you have entrusted me with in the last election," Wu said.

Wu has said he will run for re-election, and the reports about his mental health have forced him to get an unusually early start on his bid.

He spent the weekend crisscrossing his district in northwestern Oregon, which is home to a number of high-tech firms and some of the largest employers in Oregon, including Intel and Nike.

He also previewed a campaign message, declaring himself "the education guy" and a leader in science and technology policy.