to NMP, Angie
Hope you don't mind me butting it.
While I understand the reluctance to take high doses of an antidepressant (AD) taking too little can often be a bad thing. ADs do not directly ease anxiety (or depression) in the way say aspirin does for headaches. These disorders are the emotional expression of a physical brain disorder,
atrophy of parts of the two hippocampal regions of the brain caused by high brain stress hormone levels killing hippocampal brain cells and inhibiting the growth of new ones. ADs stimulate the growth of new cells (neurogenesis) and it is these new cells and the connections they form which produce the therapeutic response. For more detailed explanations see:
Depression and the Birth and Death of Brain Cells (
PDF) and
How antidepressant drugs act.
The problem with low doses for most ADs is that plasma levels need to be high enough to saturate
around 80% of the serotonin transporters to initiate neurogenesis and this must be a constant as interruptions may increase the risk of the med pooping-out. I suspect this is why the citalopram failed when you most needed it as the minimum recommended dose is 20mg. The recommended minimums are set with the ~80% occupancy rate in mind.
It is common for AD dose increases to produce significant side-effects for a few weeks. They would likely have soon diminished. It's possible that citalopram may have worked at a higher dose, but it's equally possible that it wouldn't have.
Mirtazapine is more a very sedating antihistamine than antidepressant and mostly eases anxiety by sedation. It is actually more potent than some of the meds marketed as antihistamines. It seems to work well for some, but it is very prone to poop-out and the powerful carbohydrate cravings it often induces can become a real problem.
Ian