Many of us grow happier as we age. Scientists suggest the reason for this is because we’ve learned more coping skills and are better at regulating our emotions.

However, as the saying goes, there’s an exception to every rule and one of my friends is discovering this the hard way.

Her husband has become depressed. He has a history of low mood, but it’s never been as bad as it is now.

She tells me he can’t feel any gratitude or pleasure about their 35years together, the careers they both enjoyed, or their three adult children and seven grandchildren. Indeed, she feels almost as if the past is being blotted out – for her as well as him – and that her husband has been replaced by a total stranger.

Luckily, there may be a turning point soon as his GP has arranged six cognitive behaviour sessions which should elevate his mood. In my view, this is the best possible treatment so I hope it will.

But I feel it’s my friend now who needs the help, and I’m writing about her problem because I know many of you face challenges of this nature. And actually, some of what I’m going to advise may benefit people who are carers for partners with serious physical illness too.

As I know from experience – and I’m sure many of you do too – even though we may want very much to look after our sick spouses ourselves, the reality of doing it day in day out is rarely easy.

To come back to my friend, what can she do to cope better? Probably the first thing any of us should do with a sick partner is to accept that we’re in it for the long haul – even if the condition is not terminal. As we age, it takes longer to bounce back.

The second point for anyone with a depressed partner is to remember that the negative, and sometimes even hostile, treatment they may experience from their loved one is not personal – even though it very definitely feels like it.

Some spouses who are seriously down, like to have a bit of close physical contact and will be pleased to have a hug or even sex. This can help your relationship feel more normal because you get a sense of still being valued and desired. But sadly, a sizeable number of depressed folk turn in on themselves to such an extent that they won’t even engage in a cuddle. This can feel really grim.

Why does it happen? Mostly, I think because individuals with severe low mood feel so bad about themselves that they don’t want to impose on any one in any way. This is unfortunate because most of us feel better when we get tactile with the person we love. Sometimes though, we simply have to accept it’s not happening for now. Also, it can help if you remind yourself that this lack of interest in intimacy is part of the illness and, difficult though that may be, is quite normal.

But when you feel rejected, it’s vital you get some appreciation and love from others in your life. So, make sure those closest to you know how tough the situation is, and allow them to support you.

Meanwhile, do keep talking to your partner. It’s usually not wise to say, ‘I know exactly how you’re feeling.’ This is because, almost certainly, he or she doesn’t believe that you do. So, instead say: "I realise I can’t possibly know how bad you’re feeling, but I’m here for you and will help in any way you want." You may feel ignored despite your best efforts and when that happens try not to despair because, deep down, your spouse is often grateful you’re not giving up on them.

Something else you can do is to reassure him or her of your love. But don’t overdo it. Express your care and affection two or three time a day but then leave the topic and do something interesting and beneficial for you. Make a delicious meal, or go out to see a film, or meet a friend.

You may be living with someone who doesn’t want to do anything, but that doesn’t mean you should allow your own existence to become dull and boring. Indeed, it’s important for your state of mind to build high points into it. And if he or she can’t be left for whatever reason, do enlist help from neighbours, family and friends to come to your home several times a week so you can get out and do something for yourself.

Finally, please don’t forget that individuals with depression are actually the same people as they ever were. It’s just that they’re ill. Of course, this is a dreadful patch, but you will – somehow – get through it.

So, remind yourself of all the positive parts of your past life together by looking at photo albums or reading old diaries or just thinking of the joy that you’ve had. Hold on to good memories, and hopefully you will make more of them again before long.