In the film, you spend a lot of time immersed in two specialist psychiatric units that support mothers with mental illness. What was that like?

I always feel a bit embarrassed about putting it this way, but I enjoy my work, so I actually enjoyed being on the units. I found them to be very human, warm places, although I also recognised that the people there are going through sometimes horrendous episodes of mental illness.

There have been cuts in funding across the board in the NHS, but these units are one area where authorities have maybe had a sense that they need funding. This means you’re in a place where vulnerable people are being well taken care of and they’re exactly where they should be to get professional help, and they’re being supported to the point where they can go back in the world more equipped and in a better frame of mind.

Plus, the units also have babies who are not mentally ill. So as much as the mums might be struggling, which is obviously a sad situation to be in, there are babies there as well. Very often you might see a mum with symptoms of active psychosis, which we actually have in one scene in the film, cradling a baby. And there’s one part of me thinking, ‘wow, is that safe?’, but of course it is, because they are being supervised. And even though a woman with psychosis might harm herself, it is extremely rare for her to harm her baby.