Singulair is a top-selling asthma and allergy drug approved by the FDA a decade ago, which has reached sales of $4.4 billion last year.

However, last year, FDA officials launched an investigation due to the large number of anecdotal reports suggesting a link between the drug and suicidal thoughts and behaviors. The investigation took nine months to complete.

A new analysis done by the American Lung Association that combined data from three blinded, case-control studies with did not confirm the link between Singulair and depression and suicide.

The studies involved 1,352 children and adults who took either Singulair or placebo and found no evidence of deteriorating emotional well-being among the users. Further more, the drug seemed to have quite an opposite effect early in treatment in one trial, with the users scoring higher than placebo users in tests designed to measure emotional status.

The researchers combined data from the three ALA-funded trials conducted at 20 research centers across the country. The studies were trying to determine which of the available treatments had best effects in managing asthma symptoms but they also assessed the quality of life and emotional well-being of 536 patients treated with Singulair and 816 patients who underwent other treatments.

There have been no reports of psychiatric problems, depressive episodes, or suicide thoughts and attempts among any of the study participants who were taking Singulair.

Despite all the negative publicity regarding the adverse effects of (Singulair) on suicide or emotional well-being, based on the new findings, the researchers concluded there was no evidence to support the adverse effects claims.