Anxiety
"I am taking mirtazapine for anxiety for the past 5 months now. After 3 weeks of start of this medicine, my anxiety was gone until couple days ago. All of a sudden I started getting anxiety attacks and palpitations. It feels like the effect of medicine is gone. I am seeing my doctor in a week and lets see what he suggests. Currently taking Xanax to control my anxiety. 
I have experienced that whenever I have anxiety, 5 minutes of workout (treadmill or fast walking) it does help relieve my anxiety. Try it."