The reality was completely different. As soon as I opened up about my experience, so did other people. By stopping the pretence that we were a golden couple with a perfect relationship, I became someone people would confide in. I was shocked at the number of friends who told me that they were in the exact same position.

My friends and I never talk specifics about our partner’s mental health. They deserve their privacy, and in any case, it’s not about them. It’s about us. What we needed was a safe place to admit that we don’t always get things right. That everyone, no matter how hard they try, screws up sometimes, and dating someone who has depression does not mean you’re being a saint.

The idea of getting angry with Marcus over something that is caused by his depression used to scare me. But you cannot sustain a relationship with someone if you’re too scared to criticise them. People who have depression can, and will, still behave badly for reasons other than their mental health and treating them like an ill person is a real passion killer. My challenge has been to learn to recognise the signs – the loss of appetite, the reduced tolerance for alcohol and a slight withdrawal in conversation. By knowing the signs I’ve learned how to pick my battles.

There’s a good reason why, on a plane, they tell you to adjust your own oxygen mask before helping other people. When you love someone you want to help them first, but that instinct is short sighted. ‘Self care’ is not a phrase that sits easily with me, but I’ve learned I will always be more useful if I’ve taken half an hour to watch something on Netflix while I paint my nails before entering into an emotional conversation. A small amount of selfish time is a huge investment in your ability to help another person.

When Marcus made the decision to come off anti-depressants two years into our relationship, I was terrified. It was agonising to know something that would affect my life so much was out of my control. But I respected his choice. And the world did not collapse. It has been two years since he stopped taking them. We are incredibly lucky, his illness is pretty much in the past now. There are still occasional bad days, but we get through them together. I cook, even if he says he’s not hungry, but I don’t push the point. We lie on the sofa together, and I don’t force conversation, or activity, instead, we’ll watch a film we both love.

Looking back, I’m glad that when Marcus told me about his illness, I was naÏve about it. If I had known quite how difficult living in the shadow of depression could be, I might have panicked and pulled away from him. If I had done that, I would have missed out on the most important relationship of my life. On his best day or his worst day, Marcus is still my best friend, and my soulmate.

“I won’t lose myself to my partner’s depression”