According to a recent report Statins may not be as dangerous to memory as once previously thought. A statin, which is a drug which has become well-known for its use in lowering cholesterol, was recently the subject of a report in the JAMA Internal Medicine periodical which stated that the idea that the drug might cause memory loss might be more the result of defection bias. In other words, visiting the doctor and starting a new medicine such as a statin makes people more aware of any subtle health issues they might have.
In order to come to this conclusion, Keith Mann notes that researchers compared 482,000 statin users with a comparable amount of people who were using drugs that did not lower lipids and with over 26,000 people who were lipid lowering drugs of the non-statin variety as well.
Of course, there was some data that showed that the use of statin drugs did have a tendency to lower memory ability during the first 30 days that they were taken. However, the use of non-statin lipid lowering drugs had the same effect as well.
Researchers interpreted these results in a number of ways, considering their unique history, which you can read about here. One interpretation was that either all statins cause memory loss or that the expectations of people were simply geared in that direction because of heightened awareness of the potential symptoms.