Is Depression a Singulair Side Effect?
In clinical studies of Singulair before it was approved, depression was not reported as one of the common
Singulair side effects. However, since the drug has been approved, there have been reports of depression in people taking it.
Singulair and Depression: Understanding Clinical Trials
Before most medicines are approved, they must go through several clinical studies, where thousands of people are given a particular medicine and compared to a group of people not given the medicine.
In these studies, side effects are always carefully documented. This way, it is possible to see what side effects occur, how often they appear, and how they compare to the group not taking the medicine.
In clinical trials, depression was not reported as a common side effect of Singulair, although rare occurrences of depression did occur both in people taking Singulair and in people taking the placebo (a "sugar pill" with no active ingredients). After a medication is approved and marketed, however, the manufacturer is required to keep track of side effects reported to them by patients or healthcare providers. Since Singulair was approved, depression has been reported as a possible side effect of the drug. But, because not all cases of depression are reported, it is impossible to tell exactly how commonly (or how rarely) depression occurs in people taking it.