(CBS) Alicia Adams started taking Zyprexa for bipolar disorder when she was just 18 years old. In a matter of months, she ballooned from 93 pounds to 170 and developed severe diabetes. "The depression got worse," she said. "I closed myself off from everyone - stayed in my bedroom. I didn't do much of anything." Thursday, Eli Lilly, which makes Zyprexa, plead guilty to charges so egregious they're criminal: marketing the sometimes dangerous drug in ways never proven safe or effective, CBS News investigative correspondent Sharyl Attkisson reports. Zyprexa is only FDA-approved to treat a specific bipolar disorder and severe schizophrenia. But millions have taken it for unapproved or so-called "off label" use, including: children in foster care people who have trouble sleeping elderly in nursing homes. Prosecutors say Eli Lilly engaged an army of thousands of sales representatives in widespread illegal marketing. They were "trained to use the slogan 'five at five,' meaning five milligrams at 5 o'clock at night will keep these elderly patients quiet," said Laurie Magid, acting U.S. Attorney for the eastern district of Pennsylvania. Problem is: Zyprexa has serious side effects including weight gain, diabetes, even heart failure. Shahram Ahari is a former Eli Lilly sales rep and told his story for an education project for doctors. "Seizures, things like that have happened as well. And those are, you know, pretty catastrophic side effects to have in your patient," Ahari said. Eli Lilly has agreed to pay $1.4 billion, including the largest criminal fine ever imposed on a corporation. Ironically, that's about as much as the company's Zyprexa sales in the first quarter last year.