depression
"In one night my life changed , I passed out without any reason and the next day I was depressed, I couldn't eat and sleep. I was extremely tired and my blood pressure was very high. I also had regularly heart palpitations. After several medical examinations I was put on mirtazapine:

Effect on sleep: works instantly, sometimes I did get weird dreams but after 4 weeks this also passed.
Effect on depressed mood: it took 2 weeks before I experienced that my mood was getting better, after 4 weeks my mood was good.
Effect on appetite: you get hungry but not very extremely.

Side effects: the drug makes you extremely tired but this took exactly a month before it wears off. Now my energy is completely back.

I am on this medicine for 6 weeks"