Telling someone with depression to snap out of it is like telling someone in a wheelchair to just get up and walk. There is a physical, and physiological reason, why the person is depressed, and snapping out of it is simply not an option.

I have cyclothymia - a mild form of bipolar disorder. I won't say "suffer from" because, when I do have an episode, there's a 50/50 chance it'll be fucking amazing - manic episodes, however mild, are the most amazing feeling in the world, akin to MDMA (see below). However, with the smooth inevitably comes the rough, and at times it's been very, very rough. For a while, at university, I became so convinced I was a hopeless waste of space that I was actually going to end up a pitiful heroin addict. This seemed very probable to me.

Your advice to anyone suffering from depression is definitely valid. I found that my mood improved no end by going for a walk, playing the piano or going to see friends. My milder episodes of depression could even be helped by doing my weekly big-shop. I can't say diet really helped, and exercise (by which I mean the gym) just made it worse. But hey, each to their own.

But (and this is a big but), there comes out of this a Catch 22. And that is that, during moderate to severe depression, even doing those things you've talked about becomes unbearable. You feel absolutey, completely, hopelessly, wretched, and even going outside seems like an impossible task. Don't get me wrong, you know full well that it is possible, but you can't think of anything worse than doing it. And behind these problems is the fact that you are a cunt. You will never be loved, you will never be happy, and you will be lonely, disconnected and miserable whatever you do. And no-one will care because you're such a cunt. Can you imagine feeling like that? Having what feels like an inevitable realisation that these things are true? Nothing you do can stop this kind of depression - I've had it, in this severity, three times in the past, each for a couple of months, and it's awful - easily the darkest days of my life.

And now, children, a lesson in neurophysiology. Clinical Depression is a mood disorder caused by a decrease in central levels of serotonin over the course of several weeks, many months or even years. Serotonergic neurones are found, as we might expect, mainly in areas of the brain responsible for mood, appetite, motivation, empathy and alertness. They also modulate the response of dopamine, which humans tend to like very much. It's the main point of neurological manipulation when you take cocaine or do exercise (yes, exercise is almost as addictive as cocaine). So yes, Postscript, clinical depression is caused by a chemical imbalance in the brain (sort of), and DJ, if it is caused by a lack of a certain neurotransmitter (ie serotonin), drugs will put it right.

MDMA, for instance, works wonders on the human brain. Anyone who doesn't believe manipulation of serotonin has any effect on a person should try some and then get back to me. More mild examples that cause an increase of serotonin in the CSF include paroxetine (good stuff - we used it for my dissertation) and cipralex. They simply function by either pretending to be serotonin, or preventing serotonin being taken back up into nerve cells (or both in the case of MDMA).