Having been on citalopram for anxiety and severe depression, I can totally empathise with this debate BUT, there just is not enough evidence out there to rule the drug safe to take whilst pregnant. This is why I fought hell and high water to get the therapy (CBT worked for me) I needed to come off citalopram/ads before ttc.
Ultimatly, the mental health of mum should come first. I firmly believe that 100%. But, I don't believe there is as little risk as women are being asked to just take on board from their GPs. Don't forget that your GPs are NOT pharmacologists and do not understand fully how these drugs will influence pregnancy (after all, if they did know all this, we wouldn't need spscialists half as much as we do). [As a small aside, just from the number of GPs alone that insisted the combined pill was ok for me, yet my neurologist told me 100% to never take synthetic oestrogens if you have migraines...I'd say a good 60% of GPs didn't know/didn't take the advice seriously]
Studies like this are almost impossible to do, as no 'normal' (in the scientific sense here) mom is going to be allowed to take the drug during pg to have a correct control group in place. They're also not going to risk severely depressed women to potentially have a placebo in a double-blind trial...
Anyway, I guess this is a really long winded way of me saying, if you're planning on starting to conceive, please, please fight for the theraputic angle to be in place and working BEFORE you ttc. It may take a while, and you may need to find the 'right' therapy, but please check them all out. If nothing else, a baby is not going to help your mental health. Lovely though they are, you are going to be stressed/anxious/worried about money/tired etc. etc which can only lead to you feeling worse.
A lot of women/people are just drugged with anti-depressants and given no real support to manage underlying anxieties/stresses that make depression all the worse to manage, and ultimatly cause misery and expense. It IS your right to recieve the best care possible for your mental health. If you GPs just fobbing you off with drugs and not even suggesting therapies, change GPs, this is poor advice and against guidelines. Same if you've expressed an interest in TTC. THey should be doing everything they can to fight for your mental health, not just telling you it's ok to take anti-ds and leaving it there. They should be pusing you to lower your doses (at one point I was taking 4 doses of a low amoutn a day, as I found I was crashing out towards the evening if taken late pm and morning if taken am), and pushing for you to have counselling/therapy.
Also, GPs should never just be prescribing you anything without explaining the possible problems for you, or baby...again, change GPs...this is unacceptable if it's happening.
Obviously, if baby was a bit or a suprise, then less can be done, but you're still entitled to the therapies and support anyone else is.