In 1993, tacrine became the first pharmaceutical approved by the United States Food and Drug Administration to treat Alzheimer’s disease, the most common form of dementia in the world. Often better known by the trade name Cognex, the drug cannot cure or prevent the degenerative brain disorder, but can improve the cognitive ability of some of its sufferers, especially if they are not yet in an advanced state of the disease. Tacrine achieves its effect in the body by slowing the breakdown of the chemical messenger acetylcholine, which is heavily associated with learning and memory processes. Thus, acetylcholine is able to accumulate to greater levels within the brain and remains there longer, lessening forgetfulness and other symptoms in some patients.