Until 8 years ago, I had a condition called Delayed Sleep Phase Syndrome, or DSPS. It means you never sleep before 4.00 or 5.00AM and can’t function properly until midday or early afternoon next day. It’s as if you are permanently located in another time zone.

This isn’t ‘staying up late’ or ‘having a lie in’, nor is it insomnia. With DSPS your body just will not sleep when it should, when everyone else does. You are awake, alert, you become increasingly energised and ‘buzzing’ as the night wears on.

No attempt to change it is successful long term. Some DSPS people use melatonin which helps in some cases, but dosage and timing are tricky, and some users can develop a condition called N24, in which your sleep-wake cycle breaks down completely and becomes chaotic and random.

No amount of ‘sleep hygiene’, of warm baths or ‘early nights’ or ‘staying up to chase the cycle’, does any good. Sleep is non-negotiable, and if you’re not sleepy, you can’t sleep. DSPS means you never get sleepy until hours after everyone else.

Obviously, this is profoundly disabling for any kind of normal life. Office hours are just not possible. Many 'Nightwalkers' end up in the ‘night-time economy’ or precariously self-employed freelances (which is what I did). The world is designed for ‘daywalkers’. It’s tough.

There’s very limited understanding of it, and I guess many people with it don’t know what they have has a name, is a recognised syndrome. I had no idea, I blamed myself. I think many DSPS people do. Society does, it judges them - lazy, chaotic, ill-disciplined.

It’s usually lifelong. No-one expects it to just go away. But in my case it did, quite suddenly, over a period of a few weeks, 8 years ago. I remember watching Newsnight one night (starts 10.30 PM, or it used to) and nodding off, thinking, wow, this is strange.

I ‘switched’ to a normal ‘daywalker’ sleep schedule without any effort, and it’s stayed that way for the last 8 years. I dread it returning - life is just so damn hard with DSPS - even though I grew to love the nights, the slow, velvety early hours when the whole world is asleep.

But it shows no sign of coming back. It seems to have gone.

The only explanation I could ever come up with for this had to do with a drug I take for Restless Legs Syndrome called Pramipexole (Mirapex in US), a dopamine agonist. At around the time my DSPS went away, I upped my dose from 3 x 0.088gms to 4 x 0.088gms.

A Facebook friend who also has DSPS has been ‘trialling’ Pramipexole as a possible aid for people with DSPS, and has had some success in ‘normalising’ his sleep pattern. It’s just anecdotal at this stage, but it’s possible it could help.

If anyone has had experience of Pramipexole altering their sleep-wake cycle (and not just having a transient sedative effect), I’d be fascinated to hear from you.