Singulair Psychiatric Problems More Common for Children With History of Similar Concerns: Study

Researchers call for doctors to carefully weigh the side effects when starting children on Singulair, due to risks of suicide and self-harm.

Children with mental health problems who begin taking Singulair may face a heightened risk of suffering psychiatric events after starting the medication, Johns Hopkins researchers warn.

According to findings presented at the 2025 American College of Allergy, Asthma & Immunology (ACAAI) meeting held from November 6 through 10 in Orlando, Florida, and published in the November issue of the Annals of Allergy, Asthma & Immunology, children and teens with existing mental health conditions faced a 4.5-fold higher risk of psychiatric events after starting Singulair. The study highlighted increased problems among minors with anxiety, insomnia and other pre-existing issues.

Earlier research has repeatedly linked Singulair to psychiatric side effects, including suicidal thoughts and suicide attempts. FDA clinical trial data show that more than 80 people died by suicide over a 20-year period while taking the medication, which is commonly prescribed for asthma and allergy symptoms. 

In 2020, the FDA added a black box warning about Singulair psychiatric problems, urging doctors to limit prescriptions for patients with mild symptoms, because of the drug’s heightened suicide risk.

In 2024, the New York Attorney General called on the FDA to consider more stringent black box warnings for Singulair because it poses a serious mental health risk to children and increases their risk of suicide, aggression and other health problems. Also in 2024, U.K. health regulators announced updates to the label warnings of Singulair to include the risk of serious mental health risks for young children and adults. The U.K. black box warning update highlights the risk of sleep disorders, aggression and depression.

A Reuters News report published in December 2024 suggested the psychiatric side effects of Singulair may be due to the medication’s ability to cross the blood-brain barrier, pointing out how it attaches to cells that control patient moods, which may be why it increases suicidal thoughts and aggressive behavior.

Singulair Linked to Increased Neuropsychiatric Events

In this new study, researchers from Johns Hopkins All Children’s Hospital in St. Petersburg, Florida, analyzed data from two centers involving nearly 1,000 patients ages 3 to 18 years old who were prescribed Singulair for allergies or asthma from November 2020 to December 2024.

Led by Dr. Emily Ammon, the team found that 9% of patients overall experienced mental health conditions before using Singulair. However, following treatment with Singulair, 22% of youth received medical care for depression, anxiety, suicidal thoughts and other neuropsychiatric conditions.

The data indicates children and teens who previously experienced psychiatric symptoms before taking Singulair were 4.5 times more likely to experience additional neuropsychiatric events, like suicidal thoughts, aggression, insomnia and other conditions.

Roughly 19% of patients who had suffered psychiatric conditions in the past experienced neuropsychiatric conditions after taking Singulair, compared to 7% of patients who had not suffered psychiatric conditions before taking the drug.

Researchers recommended doctors carefully weigh the risk of prescribing Singulair to patients, especially those with a history of psychiatric conditions. If Singulair is prescribed, the team calls for doctors to conduct frequent follow-up visits after the patient starts taking Singulair to monitor for psychiatric side effects.

Sign up for more health and legal news that could affect you or your family.