Sleep is a commonality of all mammals; it is a necessary daily function of life. Indeed, sleep deprivation is recognised by the UN as a banned form of torture (apologies to all new parents). And yes, even fish, such as sharks, need to sleep… however, they have the rather ingenious idea of allowing only half of their brain at a time. How much more productive would you be if half of your brain could catch 40 winks whilst in a work meeting or commuting? Although there is still much we do not understand about sleep, we do know that sleep has a multitude of important functions for living a long, healthy and happy life. Sleep is important for maintaining a healthy weight, blood pressure, blood glucose and lipid levels; it moderates anxiety and mood issues, prevents lethargy, improves immune function and much more.

A lack of sleep quality as well as duration is a risk factor for the majority of chronic diseases, including type 2 diabetes, obesity, cardiovascular disease, dementia and more. As well as reducing the activity of your immune system (see below for COVID-related details), long-term poor sleep also impairs learning and memory and may contribute to depression and anxiety. In turn, poor mental health also leads to sleep disturbance and a vicious circle of low energy and insomnia.

The answer is yes, it depends, but not much. Initially, they have a strong sedative effect. However, this wanes after 2 weeks or so and gradually tapers off. It does depend on which sleeping tablet, as well as interactions with other medications and other substances, especially alcohol. A meta-analysis, estimates they only achieve an extra 20 minutes of sleep per night. Balanced against the increased risk of falls, driving accidents and general brain fog, good sleep hygiene is a much better idea.

While there is a paucity of data looking at the effect of sleep and COVID-19, we already know that shift workers had elevated COVID-19 incidence and severity risks. The below studies highlight how sleep may adversely affect immunity:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5554442/pdf/nihms889580.pdf

Volunteers with insomnia mounted an inferior immune response to the influenza vaccine;

https://academic.oup.com/sleep/article/38/9/1353/2417971 

164 volunteers were quarantined for a week and then given rhinovirus intranasally. Those who under slept were twice as likely to get the cold. 

• Practice ‘sleep hygiene’ – your room should be cool, quiet and ideally pitch black (remember how babies like to sleep!)
• Avoid caffeinated drinks (soft drinks, tea, coffee) after 2 p.m. or perhaps avoid completely. Caffeine has a half-life of 6 hours. This means drinking a large cup of coffee at 2 p.m. is the same as drinking a small cup at 8 a.m.
• Are you reliant on caffeine because of chronic sleep deprivation…which is caused by the caffeine in the first place?
• Try to go to bed and wake up at the same time every day
• Think how little babies develop good sleep habits, we aren’t that different. We like the pre-sleep wind-down and the sleep routine, and we can all get a little cranky without sleep.
• Avoid TV, phones or other electronics 30-45 minutes before bed.
• Some phones and computers may have a blue-light-blocking app, but it is better to avoid it altogether. There is no filter for stressful news updates, social media posts or late-night work emails.
• Try not to eat too close to bedtime, 3 hours before bed would be ideal.
• Eliminate or limit drinking alcohol in the evenings.
• Try to get some natural bright light first thing in the morning. Simply standing outside on waking is enough to tell your brain what time it is and set your internal body clock for the day.