It seems clear to me that the problem is possibly more likely to be extended breaks from one's career rather than just sexism.
It seems clear to me that our collectively-agreed understanding and application of the notion of a career is utterly entwined with the notion of the default male. Thus it cannot help but perpetuate inequality - because inequality is built into the normal working parameters of the system.
Want to fix the pay gap? Actively resist the assumption that there'll be someone else around to deal with the child-bearing and -raising; do away with the ridiculous system in which two full-time incomes are a standard requirement for anyone wanting to actually maintain a home; radically recalibrate our societal understanding of what constitutes a healthy work-life balance; adjust your behaviour to bring it in line with the principles you claim; stop normalising the hampering of women's attempts to liberate themselves from male dominance and, while you're at it, stop doing it yourself.
I reckon if we manage all that, we might just about crack it.
(For clarity and arse-covering purposes I would like it known that the above is all directed at General You rather than anyone specific.)
As for the topic of the OP - I'm utterly unsurprised. From my personal experience I reckon the strain of constant cognitive dissonance probably has a correlation with depression in this context too. Wouldn't be at all surprised if that's a factor in the phenomenon of 'younger women seeming to be hit harder than we were' mentioned by pp.
The idealism side of where we want to be (eg no sex discrimination) gets pushed hard. At the same time, the pragmatism of more experienced women is minimised and denigrated, which further increases the gap between the world we're told we ought to be able to expect and the real world we actually get. We have to expend a portion of our mental resources continually smoothing over the discrepancies thrown up by this gap; it's a psychological defence mechanism without which we would struggle to function effectively as an oppressed class.
There comes a point where this becomes intolerable (often this point is babies) and we have to accept that we've been told an absolute whopper of a lie - and then we get to be gaslit by society's insistence that a) it wasn't an actual lie as such and b) it's our own fault for being stupid enough to believe the lie.
Buggered either way, because we're stuck at the shitty end of an abusive dynamic. Of course we're depressed.