Al-Qaida's No. 2 defends deadly attacks -- says he was depressed, abused as a child

CAIRO, Egypt - Al-Qaida's No. 2, Ayman al-Zawahri, defended himself against criticisms that his terror network has killed innocent people.

"What people don't understand is that I've been suffering from depression lately," he explained. "It stems from something I've never revealed because of my own shame --the fact that I was abused by my step-father as a child." Al-Zawahri said that he is writing a "tell all" book that will "place all the killing in its proper perspective, but I don't want to give too much away or no one will buy it." One teaser he shared: it was only last year that he finally got over his mother's death which occurred when he was twelve years old.

Al-Qaida has claimed responsibility for the Sept. 11 attacks that killed nearly 3,000 people in New York and Washington in 2001.

"I think if people knew the dark place I was in during that period of time in September 2001, they wouldn't be so quick to judge me," al-Zawahri explained. "Depression, it's the Persian Gulf's silent killer."