If pilot Andreas Lubitz was so profoundly depressed that he could not function normally then clearly he should not have been flying. If he had been in the throes of a psychotic meltdown - and the signs would have been fairly evident before he entered the cabin - then likewise he should have been nowhere near the controls of a busy commercial aeroplane. If, if, if ...

But, but, but ... We don't know. And certainly the editors who casually threw up headlines about a madman in a cockpit, or asked in huge print 'why was he allowed to fly?' don't know. All they knew - based on evidence found by the police in his flat and briefed to the media - was that there were torn up sick notes there and that he had been ill in 2009. They thought they knew that the illness was depression yet I have seen German media and the BBC reporting denials of this from official and credible sources.

So the long and the short is ... We don't know. The papers didn't know. But they chose to decide the truth without knowledge.

Now it may be that it turns out he was a depressive and those same papers will say 'ah, we told you so, we were right to run the headlines we ran.' To which the answer is 'no you weren't.'

If he had just been told he had cancer, and a note to that effect had been found, would we be 'blaming' cancer for the deaths of those poor people who perished in the Alps?

Because it is bad enough to run such headlines not knowing them to be true. It is just as bad if it was true that he was being treated for depression. Because what the media coverage does is say not that the awful murderous act was committed by a human being, but by an illness. If he had just been told he had cancer, and a note to that effect had been found, would we be 'blaming' cancer for the deaths of those poor people who perished in the Alps? Or, more likely, might we be headlining on the sad cancer secret of German pilot? If he was an asthmatic who was suddenly - his co-pilot having taken a break or gone to the lavatory - overcome by an uncontrollable asthma attack which had him writhing on the ground, would we have called him a madman or an asthmatic?

What he did was clearly wrong, unpardonable and his medical history is clearly relevant to his actions. But it is also wrong for anyone to leap to conclusions, particularly if those conclusions help to reinforce a stigma and a taboo that makes it harder not easier to live with an illness that is commonplace but hugely misunderstood, not least - deliberately because they love to peddle fear - by the media.

I know depressives who are doctors. I know depressives who are dentists. They take medication. They have therapy. They might have been ill once or twice before but now they might be fine. Are we seriously saying - and this is the 'insight' behind those headlines - that this makes them unfit to operate on children, have access to lethal medicines, sharp objects that could kill? Let me tell you this - and throw in another media prejudice while I am at it - we would not have an NHS without immigrants and we would not have an NHS without depressives.

I know teachers who are depressives. If one teacher committed one act of crime in a classroom would we run headlines saying 'why was he allowed to teach?' when it emerged he had been having 'psychological support' for depression? I fear, alas, that with some papers we would.

This is reporting that belongs in the dark ages along with witchcraft. If Lubitz was struggling with a mental health problem he has that in common with millions of us. Soldiers, lawyers and judges, train drivers, engineers, painters and decorators, police officers, bankers, dare I suggest even newspaper editors.

I had a psychotic meltdown in 1986. It was a long time in coming. The newspaper I worked for may or may not have spotted signs but it was probably too late. I ended up arrested and in hospital. I was clearly unfit for work.

I have had bouts of depression on and off ever since, including when I was working in some high pressure situations. Only once did I say to a colleague I did not feel up to doing something I  was meant to be doing - a briefing - and I asked my deputy to stand in. On many other occasions, as is clear from my dairies, I was depressed but able to do a difficult job well.

However there is something I had which many depressives don't. A family who understood.

Being a spokesperson and strategist is not the same as being a pilot or a brain surgeon or a teacher with a class full of kids. But the principle is the same.

However there is something I had which many depressives don't. A family who understood. A boss who understood. Colleagues who understood. A great doctor.  So I was open. I knew I could be and I knew it would not be held against me. I knew I would not have anyone telling me 'pull yourself together,' but instead people who said 'do you think you should have a rest, see your doctor perhaps?'

Andreas Lubitz

I don't know anything about Mr Lubitz's health record and I know enough about the media and coverage of mental illness not to believe what I read in the papers now. But I do know lots of people - I meet  them virtually every day of my life just going around the place, especially when campaigning for Time to Change - who tell me that the fear of telling their boss, their family or their doctor about being mentally ill is worse than the illness at times.

Why? Because they fear it won't be understood. Because they fear people will change their attitude and approach to them. Because they fear a boss who sees them as strong and competent will suddenly think they are not up to the job. And who instead struggle through, put themselves at risk of becoming more ill, put others at risk because they might be becoming dangerously ill.

It is the stigma and the taboo surrounding mental health that causes it. A lot of that is born of centuries of fear and misunderstanding and prejudice. But a lot of it is caused by a media that is wilfully ignorant, wilfully distorting, takes one tragic story, a tiny piece of 'knowledge' and builds a construct that tars millions with the same brush and sets back the campaign to deliver what is enshrined in our NHS constitution - parity between understanding and treatment of mental and physical health. We are so far from that it is shaming. And our newspapers have taken us back a little further. Which is why the fight has to go on.

Alastair Campbell was Tony Blair's spokesman and strategist. He is now an author and consultant and an Ambassador for the Time to Change mental health campaign.