Part II is a 16-week treatment phase subjects will be randomly assigned to either rimonabant or placebo for a 16-week period. The medication will be given in unmarked capsules so that subjects will not know which medication they are receiving. Only the pharmacist will know which medications subjects are receiving. If an emergency occurs we will break the blind and give appropriate care. This phase will require one visit every week and each visit may take up to 2-3 hours. Subjects will be examined every week to check symptoms side effects. Subjects symptoms will be evaluated using specially designed rating scales, to ask about their daily experiences and feelings. Evaluations that occur every 4 weeks may take about 2 hours. At week 8 and week 16 laboratory tests will be repeated. These tests will be compared to the baseline tests taken in Part I. The end of study tests may take up to a total of 8 hours and may require 3-4 visits. All testing is done for research purposes only and would not be performed if subjects were not participating in this study. The total number of visits requested for this study will be 16-20. When subjects undergo neuropsychological testing, we will examine their ability to learn and remember numbers and words to pay attention and to quickly perform motor tasks. A motor task is when you use your hands to perform a task such as placing pegs into a piece of wood. These tests will take about 2 hours and are done at the beginning of Part I and the end of Part II.