Are you suffering from 'sleep debt'? Six simple ways to make sure you get quality shut-eye

We need to get more sleep. The US National Sleep Foundation recommends that adults need seven to nine hours sleep in every 24 hours - but very few adults meet this requirement. Our sleep needs vary at different stages of life: newborns need 14 to 17 hours sleep; preschoolers need 10 to 13 hours; school-aged children need nine to 11 hours, and teenagers need eight to 10 hours.

Sleep has huge effects on emotions, mood, appetite, energy and wellbeing. The NHS advises that chronic sleep debt increases risk of long-term mood disorders like depression and anxiety. When people with anxiety or depression were surveyed to calculate their sleeping habits, it was found that most slept for fewer than six hours per night. In addition, mental health problems like depression can affect sleep, resulting in difficulty falling asleep, interrupted sleep, early morning waking, and unrefreshing sleep. This is a vicious cycle that affects all aspects of a person's functioning. So, if you have depression or anxiety affecting sleep, it is important to seek treatment for this.

There are many steps everyone can take to improve their sleep. The UK Sleep Council and various other online resources have plenty of advice about getting a good night's sleep.

• First, your bedroom should be dark, cool (around 16-18°C), quiet, uncluttered and free of gadgets. This means removing televisions, computers, tablets, phones and other pieces of electronic equipment. Your bed should be big and comfortable, and you should change the mattress every eight years.

• Second, lifestyle matters hugely. In the evening, reduce the intensity of light in your home (using dimmer switches or low wattage bulbs); establish a bedtime routine and regular sleep pattern; avoid alcohol; avoid naps during the day; and don't use computers, mobile phones and televisions in the hours before bedtime.

• Third, be aware that stress and worry affect sleep. One way to calm the worries is by counting sheep or reciting the alphabet (in your head if you've a bed partner; in a whisper if you do not). Breathing exercises are also helpful: gently counting to 10 on the in-breath, counting to 10 on the out-breath, counting to 10 on the turning of the breath, and then starting again.

• Fourth, diet matters. Caffeine, alcohol, sugar and cigarettes all hinder sleep. It is important not to be either hungry or too full when going to bed. Food affects people differently, so if you think a particular food affects your sleep, keep a careful 'food-and-sleep' diary to identify patterns. In general, foods that are rich in tryptophan often assist with sleep. These include chicken, turkey, milk, dairy, nuts and seeds. Many people drink hot milk before bed.

• Fifth, exercise helps. From a sleep perspective, the best time to exercise is in the morning, ideally outside. Adults should get either 150 minutes of moderate aerobic activity (e.g. cycling, brisk walking) or 75 minutes of vigorous aerobic activity (e.g. running, tennis) every week, and should also do strength exercises on two or more days, working all the major muscles (legs, hips, back, abdomen, chest, shoulders and arms).

• Sixth, relaxation exercises can help set the scene for sleep. One good exercise is the 'body scan' which involves focusing your attention at the top of your head and then moving your thoughts and focus down your body, systematically noting each part of your body as you progress, and consciously relaxing it as you go along. It is important to be systematic, mindful and slow.

If you go to bed and can't get sleep, there is a '20-minute rule' that can help. If you're lying in bed without sleeping for 20 minutes, get up and read a book for 20 minutes - not an electronic book, but a book printed on paper in the traditional fashion. Do not watch television, drink tea or coffee, smoke cigarettes, or look at a phone, tablet or computer. After 20 minutes, go back to bed and try again to sleep. If that does not work after 20 minutes, repeat the procedure until you fall asleep.

If you have a bed partner, it is important to discuss sleep problems with them. You may need to remove yourself from a shared bed or send your partner to the spare room until your sleep pattern is re-established. Separate beds might also help, as might seeking medical advice about snoring.

If you have persistent problems sleeping, it is wise to visit your doctor, to see if other problems (e.g. hormonal changes) are affecting sleep. For some people, sleeping tablets or other medications can help, but these need to be taken in the context of an overall approach to sleep that also includes good sleep hygiene.

Good sleep has enormous benefits for mental health, wellbeing and life satisfaction. As the Dalai Lama points out: "Sleep is the best meditation".