We've been awaiting a new placement since Romeo went back to his disorganised mother.

We worried about him for some time, his mum is all over the place, but it's so what he wanted. He's a tough nut, he'll be ok.

The phone rang.

"Would you consider taking a child who...?"

The child isn't a child actually, he's older than that. Mind you, most foster children are somehow older than their years. However this young fellow shaves.

His story is this;

He's the offspring of what used to be called a mixed marriage. I believe the current preferred term is British African. A child could be British Indian or British Asian and so on, I imagine there are any number of variants. I remember my grand-dad used to be against what he called mixed marriages. He was a kind man, he said "It's not fair on the children". That was back in the sixties, and I knew what he meant. Things, you would think, have changed, but apparently not enough; the child isn't sure who he is. He found it hard to make friends round his way. He feels he doesn't belong.

I remember thirty years ago visiting a special unit for disturbed teenagers and was struck by the high percentage of youngsters who were as described above.

Our new boy, I'm going to call him Glen, is one such.

Glen has depression.

That simple fact was clear from the information we were emailed about him before I said yes.

We've worked with plenty of children who found the circumstances of going into care upsetting. Many others had complicated feelings which were more entrenched since they'd experienced difficulties in their real home over a period of time.

Glen is the first foster child we've had who deserved the diagnosis that he is more than sad and upset, he's depressed.

As a society we are afraid of mental illness as if it means danger, or maybe is contagious. A lot of people still think there's shame attached, not just to the person who has the illness, but to those around them who might have been part of the cause. Parents of children with mental illness suffer a lot of unnecessary guilt and suspicion, as if they don't have enough on their plate.

Are we worried that Glen might represent any kind of danger? No.

We went through his profile with a fine tooth comb with our social worker. Glen has no anger issues, quite the reverse; he has difficulty exerting himself in any way, perhaps because he has very low self esteem.

He does not appear to be a danger even to himself; there has been no self-harm. Definitely no talk of taking his own life.

He stays in his room as much as possible, so to begin with we're letting him eat up there. He ventures out when the family are all at school and at work, and so long as it's just me. I keep off his case, don't barrage him with questions and stuff. I try not to put my foot in it. He gets more comfortable each day.

My job is to keep him on his medication; mild, but always under review, and to get him to therapy twice a week; one is a one-on-one with his counsellor, the second session is group. We'll get him into education if and when it's right for him.

I've been Googling like crazy (sorry, I'll re-phrase that - see how easy it is to put your foot in it...)

Try again;

I've been Googling day and night; all the latest thinking about mental illness in young people. The apparent increase, especially in teenage men, is shocking. Whatever the reasons, even if one of those reasons is that we are only just learning to identify those who are affected, it's soon going to be as big an issue as the surge in dementias among our older citizens.

Centuries ago the human race was almost wiped out by diseases of the body. Nowadays we are so much better at tackling what used to be called plagues.

In a century's time we might be on top of the causes and proper treatments of the mental illnesses that are now starting to overwhelm our young.

The thing I'm starting to believe is that while most physical ailments fit into a neat category, with an equally neat prescribed treatment; the fact is that I think every mental illness is as unique as the person. And as if that's not complicating things enough; I believe the illness changes not just from day to day, but almost in the blink of an eye. I'm talking about more than mere mood swings here.

What to do then, for Glen and other looked after-children like him?

I don't know. Keep up the love. Be patient and understanding. Look after my own happiness (being at home all day with no-one to talk to but someone whose take on reality is askew can be a bit gruelling).

Look after my family's happiness.