We often think that the weather can be held responsible for our mood. I’m sure you all know someone who claims that his or her mood swings depending on the weather, with cold and rainy days making them feel low and miserable and sunny days making them feel all happy and excited. You may think they are exaggerating but hold on, they may have a point!
In the Diagnostic and Statistical Manual of Mental Disorders DSM-V, mood disorders “with seasonal pattern” were recently classified as disorders that occur at a specific time of the year and fully remit otherwise. Symptoms often consist of insomnia or a tendency to over sleep and over-eat, irritability, decreased appetite or weight gain, lack of energy, difficulty concentrating or completing tasks, social withdrawal and decreased sex drive. Taken together, all of these can lead to depression, pessimistic feelings, hopelessness and an overall lack of enjoyment in all our daily activities.
But why is that?
It has been argued that those symptoms are remnant of a hibernation response in humans; as food was scarce during our prehistory, a tendency toward low mood during the winter months was adaptive by reducing the need for calorie intake. Similarly, in other species, activity is diminished during the winter months in response to the reduction in available food and the difficulties of surviving in the cold.
If you think about it humans may be particularly affected by the lack of light during the colder months – for instance, studies have found that when sufferers are exposed to light (e.g. during the morning hours), they tend to feel better. This also suggests that bright light therapy may be an effective treatment. Specifically, light-related alterations of the duration of melatonin secretion may affect mood cycles; light therapy thus uses a light box which emits far more light than a normal lamp or a computer-controlled heliostat to reflect sunlight directly into the windows of your home or office.
Finally, another explanation is that vitamin D levels are too low when people do not get enough Ultraviolet-B on their skin. An alternative to using bright lights is to take vitamin D supplements.
Maybe it's just me?
Recently, an interesting study by Klimstra et al. (2011) looked at different types of personality and how each one is affected by the weather. They found 4 distinct groups:
•Unaffected – roughly 50% of the participants reported that their mood is unaffected by the weather.
•Summer lovers – mood improves with more sun and higher temperatures. Bring it on Ibiza!
•Summer haters – people who are happier when there’s more rain, less sun and lower temperatures (unsurprisingly though, they often get overlooked).
•Rain haters – mood is not affected by a change in temperature or sunshine, but the participants just felt less positive when it was raining. And of course, rainy weather makes it more difficult to get outdoors. In addition to facilitating exercise, simply spending time outside on a sunny day has been associated with lower stress levels and increased well-being.
So many of us seem to be affected by the weather, just in different ways. So really it depends on our own personality as to whether our mood will be affected by the weather. If you're in a good mood, the bad weather won't bring you down too much, but, if like me you feel better when the sun is burning and you don’t have to cover up too much all the time, you can look forward to this coming weekend when the UK will see a last hurray of summer! Just don’t expect it to last too long.