Do clock changes linked to daylight saving time make us sadder? What science has to say about this
With the yearly arrival of winter time, the controversy returns once again. Why do many people feel sad after the clock change, even though they gain an extra hour of sleep?
Since 1918, in Spain, clocks are changed twice a year: every summer and every winter. The change to winter time always takes place on the last weekend of October, when the clocks are turned back one hour. The summer time change takes place at the end of March.
Therefore, and although the European Union has been debating for years whether this should be abolished, every March and October we need to adjust our clocks. In fact, Spain is not governed by the time zone that would naturally match its geographical position. By location, Spaniards would need to set their clocks to the same time as Portugal or the United Kingdom.
The change to winter time means that everyone can sleep an extra hour that night, but this one-hour delay makes many people feel more tired and depressed. Why? Part of the answer lies in melatonin.
How the body reacts to these time changes
The body is regulated by an internal biological clock that is located in the hypothalamus, a specific area of the brain. This clock is responsible for setting circadian rhythms; i.e. the rhythms that regulate and define sleep, appetite or mood.
This biological clock is synchronised, on a daily basis, with natural daylight, by means of special cells in the retina. When that light changes, for example, due to having set our clocks to a different time, the human body needs to readjust.
In this process, melatonin is essential. This hormone starts up its production in the evening and alerts the body that it is time to rest. When clocks are changed, melatonin secretion is altered and, consequently, the internal clock is out of alignment. This triggers a range of physical and emotional effects.
Mood swings and depression linked to time changes
Persistent tiredness, low mood, sadness, irritability, increased appetite, isolation, or depression. Those are just some of the common symptoms of seasonal affective disorders, also known as SAD.
Linked with the change of season and daily schedules, this disorder affects between 1% and 10% of the population, depending on the geographical area. In Spain, for example, it is more common among the elderly or children.
It can also happen when you endure sudden time changes, such as when traveling to a country in a very different time zone. In this case it is known as jet lag. In that situation, the body also needs to readapt.
Apart from depression due to the time change, there are also other negative health consequences of this social change:
- Loss of concentration and memory
- Increased cardiovascular risk
- Compromised immune system
- Changes in appetite or digestion
- Decreased energy
- Tiredness or drowsiness during the day
- Changes in blood pressure
- Headaches
- Nervousness
- Trouble falling asleep
Adapting to winter time
Although we cannot avoid these imbalances altogether, there are some easy-to-follow habits and strategies that can help you better adjust to the new daily schedule and, above all, minimize its impact on your health.
- Exposure to the sun: Even if only for a few minutes, it is important to get some sunlight daily.
- Exercise: Staying active helps regulate our biological clock, especially if we exercise outdoors.
- Create a nightly routine: Reading or meditating before bed improves the quality of sleep.
- Keep all screens well away from your bed: Blue light from electronic devices slows down melatonin production and makes it difficult to sleep.
- Plan meals: Avoid excessive carbohydrate intake before bedtime. Seasonal fruits and vegetables are your best allies to achieve a good diet.
- Socialize: Talking to friends or family improves mood.
- Start routines ahead of time: It is advisable to gradually adjust your schedule a few days before the change takes place.
Ultimately, turning the hands of the clock forwards or backwards will alter people's biological rhythms. The effects are mild and transitory – they usually last just a few days – but it is important to pay attention to those symptoms that involve mood and sleep as they might end up becoming a longer-term problem.
