The study, published in the Journal of Environmental Psychology, compared Sweden’s average temperature for every month between 1991 and 1998 with sales of the most common type of anti-depressive.
The results showed that the lower the temperature in the month of July, the higher the sales of anti-depressives.
“We don’t believe that the weather itself makes people depressed. It’s more the case that bad weather in the summer prevents people who already suffer from chronic stress from recovering sufficiently,” researcher Terry Hartig of Uppsala University, who carried out the research with American colleagues, told Dagens Nyheter.
Spending time in the countryside has shown itself to be a particularly effective way of recovering from stress. Poor weather leads people to spend time indoors instead, meaning the stress remains, which can lead to depression.