Lindsay Lohan

The vice: Alcohol and drug use

In 2010, the star served two stints in jail for violating probation -- first, by missing court-ordered alcohol education classes then for failing a drug test -- before checking into the Betty Ford clinic for treatment. Whether the time in rehab will help her stay clean remains to be seen. If it doesn't, the possibility of sleeping on a hard cot again may be the least of her worries. Alcohol abuse can cause hepatitis, liver failure, dementia, stroke and anemia, plus depression and anxiety disorders, according to Vanessa Maier, MD, MPH, a family medicine practitioner at University Hospitals Case Medical Center in Cleveland, Ohio.  The good news for "Li-Lo" and others struggling with addiction: Research shows that recovery is possible and addicts can go on to lead healthy, fulfilling lives.