(I'm a 40yo male 140lbs and I take no other meds.) I've been taking singulair for an allergy for a couple months and suddenly started having strange dreams and nightmares. For me this was so unusual that I immediately suspected the new medication might have something to do with it. I entered 'Singulair and nightmares' into google and found myself here.
Thanks for the info everyone. I'll stop taking it and see what happens.