My mum worked FT from when I was about 3.5, She had awful PND after me, and whilst it didn't return after she had my sister (I was almost 3), she's since said she went back to work to try and prevent it more tan anything, and that her 3.5 years at home were just dreadful for her. She loved us very much but found a life of housework, 'mum friends', toddler groups and suburbia was impossible for her. She didn't have some well paid high flying career life btw, just an office job in the civil service.
I actually liked her working FT. She was out before I got up, and Dad was far more laid back at the getting ready for school stuff (also worked FT as a teacher so did all holiday childcare too) than she was, so fewer arguments/stress. Mum would get back in at about 5.30 as tea was almost ready (Dad would prep it, Mum would finish it off and kids wash up). Once of an age where a childminder wasn't needed until 4.30ish, I noticed my friends' mums would be keeping a beady eye on who they walked home with, nagging them to hurry home, don't talk to so-and-so in the park... his Dad's trouble, you get the idea... I was trusted more and was better prepared for the world as a result maybe?
The best advantage of my mum working FT though was that we had a hell of a lot more disposable income than my peers' families. We could have managed, in those days, on my Dad's salary, though it would have been tight. But we had a much nicer house, eventually two cars, two package holidays a year plus weekend mini-breaks to educational places, nicer newer clothes - a good move in her case, and ours really.
I had to go back to work when DS1 was 7m old, I was the sole earner and exP had a new business which earned nothing yet. DS1 coped fine, he enjoyed PT nursery very much, ,and had fun with exp PT too. I felt very tirn as I loved my job, but was so so sad at being away from DS1 all day and missed him awfully at first. But - no choice other than homelessness and we all got used to it ok. I was made redundant before DS2 so am still at home with him at 21m. Like my mother, I realise that homemaking aint really for me, no matter how much I adore DS2. I also need the money as am now single parent!