[TLDR; this medication can cause severe mental health side effects.](https://www.ajmc.com/view/fda-steps-up-warning-for-montelukast-for-risk-of-mental-health-side-effects)

PLEASE UPVOTE FOR VISIBILITY. 

I have been taking this asthma/allergy medication for about 3 months. 

I have a history of depression, anxiety,  and OCD for which I have been taking medication for many years. It’s been under control. Entirely controlled. 

For the last few months I have been fighting depression, my anxiety has been through the roof, I’ve made poor decisions/lacked executive function, been *extremely* anxious, I barely ate for 2 months, my sleep has been a mess, I’ve felt listless and out of it and I’ve been emotionally unstable. 

Come to find out that Singular (generic: montelukast) is supposed to come with a label warning of possible moderate to severe mental health side effects, and that physicians are supposed to discuss this prior to prescribing. 

I was never warned and the bottle has never carried a warning. My PCP overlooked this (not here to discuss this failing) and the pharmacist also overlooked it. 

I have been off it for a few days now and already feel like a different person. 
I looked up “Singulair” in this sub and see posts 2-8 years back of people concerned about depression who also were taking Singulair. 
I am sharing this in the hope to help someone/anyone else who may be unaware and struggling. 
For clarity, it’s not a drug interaction issue. It’s the drug itself.