Pulling an all-nighter can reverse depression for several days, study claims

Most people associate sleepless nights with feeling cranky the next day.

But a good night’s sleep can even reverse depression for several days, a new study suggests.

Sometimes, even though the body is physically exhausted, the brain feels groggy and agitated – that tired and wired feeling that some people will be familiar with.

Experts say this may have to do with the brain chemical dopamine, which plays a role in pleasure and reward.

According to the researchers, the effect of missing a night’s sleep is like a powerful antidepressant that keeps the mood going for several days.

In the study, mild and acute sleep deprivation was induced in mice before their behavior and brain activity were analyzed.

Not only did dopamine release increase during the period of acute sleep loss, synaptic plasticity (the ability of neurons to change their connections) was also improved – literally rewiring the brain to maintain the vibrant mood for days to come.

The findings, from neurobiologists at Northwestern University, could help scientists better understand how moods naturally change.

They could also lead to a more complete understanding of how fast-acting antidepressants like ketamine work and help researchers identify previously unknown targets for new antidepressants.

Author Professor Yevgenia Kozorovitskiy said: ‘Chronic sleep loss has been well studied and its uniformly harmful effects have been extensively documented.

‘But short-term sleep loss – like the equivalent of a student pulling an all-nighter for an exam – is less understood.

‘We found that sleep loss has a powerful antidepressant effect and rewires the brain.

“This is an important reminder of how our informal activities, like a sleepless night, can fundamentally change the brain in just a few hours.”

But the researchers caution against pulling an all-nighter to brighten a gloomy mood.

Prof Kozorovitskiy said: ‘The antidepressant effect is transient and we know how important a good night’s sleep is.

‘I’d say you’d be better off going to the gym or going for a nice walk. This new knowledge is more important when it comes to matching someone with the right antidepressant.”

The researchers found that after a sleepless night, the mice’s behavior changed and became more aggressive, hyperactive and hypersexual, compared to animals that experienced a normal night’s sleep.

The activity of dopamine neurons, which are responsible for the brain’s reward response, was measured and researchers found that activity in animals was higher during the short period of sleep loss.

They also found that the antidepressant effect lasted except when dopamine responses were silenced in the prefrontal cortex – the front of the brain.

Prof Kozorovitskiy said: ‘That means the prefrontal cortex is a clinically relevant area in the search for therapeutic targets.

‘But it also reinforces the idea that has emerged in the field recently: dopamine neurons play a very important, but very different role in the brain.

“They’re not just this monolithic population that just predicts rewards.”

Most of the behaviors, such as hyperactivity and increased sexuality, disappeared within a few hours of acute sleep loss, but the antidepressant effect lasted for a few days, according to the study published in the journal Neuron.