Author Iris Chang's apparent suicide at 36 stunned many people who were impressed by the young journalist's international best seller, "The Rape of Nanking," and her activist work speaking out against imperial Japan's war crimes.

Conspiracy theories abounded after her 2004 death by gunshot on the side of a Northern California highway.

Many thought the years Chang spent studying accounts of war atrocities had gotten to her. Some even speculated that right-wing Japanese had murdered the Chinese-American author in retaliation for her work raising awareness about Japan's subjugation of China in the late 1930s.

At the time of her death, Chang was by all appearances a happily married mother to a 2-year-old boy, balancing a quiet life with her college sweetheart and a successful career. After completing her third book, "The Chinese in America," in 2003, she started work on a book on Japan's mistreatment of prisoners of war in the 1942 Bataan Death March.

Few people outside Chang's immediate family knew that she was becoming increasingly paranoid and was institutionalized for a short time.

To write her book "Finding Iris Chang: Friendship, Ambition, and the Loss of an Extraordinary Mind" (Da Capo Press, $24), Paula Kamen interviewed friends and acquaintances and combed through personal correspondence and library archives to find out how a woman who appeared to be leading a perfect life could have committed suicide. Kamen had been Chang's friend since their days as journalism students at the University of Illinois.

The result is a nuanced portrait of a brilliant but troubled person who — Kamen concludes — decided to kill herself in a manic phase of bipolar disorder brought on by genetics, fertility treatments and extreme stress.

But the book has problems: Almost from page one, Kamen acknowledges a long-standing rivalry with Chang and repeatedly inserts uninteresting details about her own life into the book, seemingly continuing to compete with her dead friend.

These self-indulgent ruminations take up page upon page, while Kamen rushes through fascinating topics such as the medical community's failure to consider cultural and physiological differences when treating Asian-Americans for mental illness.

The book's greatest appeal may be the long passages in which Chang, with her always interesting turns of thought, speaks in her own voice through transcribed conversations, early poems and stories, and quotes from interviews with the press.

"Some people as they write, they may dwell on love or the acquisition of great riches, but for some reason I seem to be bothered whenever I see acts of injustice and assaults on people's civil liberties," Kamen quotes Chang as saying in a 2003 interview with the Web magazine Identity Theory.