Mirtazapine
"I was prescribed venalfaxine and after 10 days I experienced terrifying symptoms. I stopped taking it immediately, to the annoyance of the psychiatrist who had given  it. He then prescribed mirtazapine which I took at 15mg for 2 weeks with some success.  After 10 days on Mirt I had three nights of heigtened anxiety, although nothing as bad as before taking the mirt. The psychiatrist then suggested upping my mirt to 30mg. I did this for 2 nights and felt dreadful. Last night I reverted to 15mg and I intend to stay on it. I think it is worth remembering that taking drugs that 'mess with our heads' is not like taking pain killers. If 15mg is good it does not mean that 30mg is better."