Popular asthma medication Singulair linked to serious mental health concerns for adults and children

mother giving her daughter medicine Singulair concerns
Aleksandra Suzi/Shutterstock

Singulair (generic for Montelukast) may seem like the ideal medication for kiddos (or parents) with asthma–it’s an easy-to-use daily pill that helps prevent asthma attacks and relieves allergy symptoms. But a recent New York Times report has shed light on the concerning connection between mental health and Singulair.

The Times article shares harrowing stories of parents who describe hallucinations, aggression and hostility, obsessive-compulsive behavior, nightmares and thoughts of wanting to die in children as young as 5 after taking the drug. One mother describes the disturbing changes she noted in her son’s artwork, where his drawings only returned to normal after stopping the medication.

Used by close to 1.6 million children, Singulair treats asthma and severe allergies by reducing inflammation that can cause breathing problems. Initially approved in 1998, its popularity increased in the early 2000s as an alternative to steroid inhalers. Now, it’s unclear if the benefits outweigh the risks.

A black box warning for serious mental health risks

The FDA has been reviewing the safety of Singulair since 2007, when reports of mood changes and suicidal thoughts first emerged. By 2020, the FDA required the medication to contain a

black box warning–the highest level of caution–for possible severe mental health side effects.

In theory, black box warnings should be clearly communicated to patients and their healthcare providers, but according to reports, many parents and even doctors are still unaware of the potential risks, with some indication that doctors weren’t given proper training by the maker, Merck.

Merck has faced multiple lawsuits alleging that they’ve downplayed the connection between mental health and Singulair, but the FDA has not taken significant action beyond issuing the black box warning. While some experts argue that this warning is enough, others believe that more needs to be done as most of us skim over the fine print found in the pages of medication inserts, if we read it at all.

Studies suggest that Singular may cross the blood-brain barrier

Animal studies indicate that the drug crosses the blood-brain barrier, where it could interact with cells in the brain and interfere with neurotransmitters that influence mood and behavior.

The FDA continues to monitor health records for reports of adverse mental health effects, but current studies are limited and weren’t designed to measure mental health outcomes. Many studies that found a connection rely on observational research, which means they can’t prove that the drug was the cause, only that there is a correlation.

In the meantime, as with any medication, parents should be aware of potential risks. If you have concerns about mental health and Singulair, talk to your pediatrician and monitor closely for any changes in mood or behavior.


Marques CF, Marques MM, Justino GC. The mechanisms underlying montelukast’s neuropsychiatric effects – new insights from a combined metabolic and multiomics approach. Life Sci. 2022;310:121056. doi:10.1016/j.lfs.2022.121056