(Bloomberg) Illinois Representative Jesse Jackson Jr. resigned from Congress after serving almost 17 years, citing his “deteriorated” health and a federal investigation into his conduct.

In a letter today to House Speaker John Boehner of Ohio, Jackson said he’d made “my share of mistakes” without specifying what he’d done wrong. The resignation is effective today “in order to focus on restoring my health,” the letter said. Jackson, 47, has been treated for depression since taking a medical leave from Congress in June.

“I am aware of the ongoing federal investigation into my activities and I am doing my best to address the situation responsibly, cooperate with investigators, and accept responsibility for my mistakes,” Jackson, a Democrat, wrote in the letter. “They are my mistakes and mine alone.”

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