A report in the journal Pharmacology Research & Perspectives indicates that a popular asthma medicine known as Singulair (montelukast) may be linked to mental side effects, including depression, suicidal thinking, aggression, headaches, anxiousness, abnormal dreams, hallucinations, and insomnia.

Singulair is used to treat asthma and allergies, and is taken once daily as a pill or as dissolvable granules.

Since 2009, the medicine has carried an FDA warning about its mental side effects.

The recent study used a large database from more than 120 countries, and included nearly 18,000 reports of the drug’s side effect frequencies.

The rate of suicidal thinking increased 20-fold and the rate of nightmares increased 22-fold in people taking the drug. Those taking Singulair also had double the risk for headaches.