To answer your question, it is not entirely clear how Mirtazapine (Remeron) works, since no other medications work exactly like it. It is thought that the anti-depressant effects of the drug are due to its actions on serotonin and norepinephrine. These are chemicals used to send messages between nerves. If serotonin or norepinephrine levels become unbalanced, it can cause a variety of conditions, including anxiety and depression. Certain receptors decrease the levels of serotonin and norepinephrine released by the nerves. Remeron blocks these inhibitory serotonin and norepinephrine receptors, causing more of these chemicals to be released. This may help to relieve the symptoms of anxiety and depression. Remeron blocks several different kinds of receptors, including serotonin, norepinephrine, histamine, alpha, and muscarinic receptors.
Once started, most psychiatrists/physicians want their patients to be on an anti-depressant for at least a year. However, for many people, anxiety disorders and depression can be a chronic condition, requiring possible lifelong use of anti-depressants. Research has shown that individuals that start and stop, start and stop anti-depressants, run the risk of having to be on increased dosages to obtain the same previous effects, or not having the anti-depressant work at all.
Remeron can make many people very sleepy, and therefore should be taken at bedtime. It can also make one's appetite go through the roof, so weight gain can be a real problem for some.
I hope this helps to answer your questions, GA. The very best to you!... Chuck