Hi Jess
Taz is right that some HRT has progestogens which cause pmt like side effects including anxiety so better to find out if this is still the cause of your anxiety than go on to anti-depressants as it could be one medication making you anxious and then another trying to deal with that anxiety, when a change in HRT type might help!
Personally when starting HRT I think it is better to start on a cyclical HRT (ie one that causes a bleed) even if post-menopausal, because then it is easier to see if the progestogen is causing the problem.
In your case you are taking norethisterone - a synthetic progestgoen that does disagree with some women - along with the oestrogen.
Rather than take the citalopram - I would try a different HRT type. If you don't want to go onto a cycle at this point I would suggest Femoston, because the progestogen in this type ( called dydrogesterone) is very close to our own progesterone and causes fewer side effects. I would urge you to try this one and stop the ADs rather than become dependent on them without knowing whether it's the HRT type causing or adding to your anxiety. It is listed here:
http://www.menopausematters.co.uk/postmeno.phpIn the meantime can you try mindful techinques to cope with your anxiety while you try out a different type? There is a site called nomorepanic that someone on here found a few months ago which I understand is helpful
http://www.nomorepanic.co.uk/Also this exercise which a former member found helpful (scroll back to the beginning), as did other members (3 2 1 anxiety exercise):
http://www.menopausematters.co.uk/forum/index.php/topic,8454.0.htmlHope this helps
Hurdity x