NEW YORK - Rhode Island U.S. Rep. Patrick Kennedy, son of the late Sen. Edward Kennedy, is writing a memoir.

Houghton Mifflin Harcourt announced Tuesday that Kennedy's "Coming Clean" is planned for next fall. Kennedy, who has battled depression and alcohol and drug addiction, will write "a truly revealing, intimate portrait," the publisher said.

"I realize that I have an enormous opportunity to turn my biggest liability - my illness, which includes addiction - into an asset to help countless numbers of Americans who quietly suffer and cannot afford treatment or risk telling their employers," Kennedy said in a statement. He will co-author the book with political reporter Mary Ann Akers, who has written for The Washington Post and Roll Call.

"That's why I'm writing this book. I hope that by telling the real story of my own personal struggle, I can kick off my lifelong mission: to destigmatize addiction and other neurological ailments, and break down the barriers between research and treatment of different types of brain disorders."

The 43-year-old Democrat, who shared his father's passion for health care reform, is retiring from Congress after eight terms and plans "a major endeavor to fight all neurological disorders, from addictions to PTSD to depression, among many others," according to Houghton Mifflin.

"Coming clean about his family and himself is an important first step in his initiative to help the millions of Americans who suffer from similar afflictions."

Sen. Kennedy died last year, shortly before the release of his memoir "True Compass," in which he wrote that Patrick had a shy nature but seemed to love campaigning. Patrick has long been regarded as more comfortable being an advocate for the mentally ill and speaking openly about his own struggles with depression and substance abuse. The younger Kennedy has said that his father's death from brain cancer last summer helped convince him he didn't need to hold public office to make a difference.

Patrick Kennedy will not be the first of his generation to write about the pressures of growing up in one of the world's most famous families. Cousin Christopher Kennedy Lawford, son of Patricia Kennedy Lawford and actor Peter Lawford, described his own struggles in "Symptoms of Withdrawal," published in 2005.