Researchers analysed climate data, access to healthcare and mental health indicators to determine where seasonal changes may have the greatest psychological impact.
New Zealand’s ranking was influenced by its somewhat high annual rainfall of 1732mm, and average yearly temperature of 10.46C, two environmental factors commonly associated with seasonal depression.
However, our relatively strong healthcare system helped keep our risk score lower than many other nations higher up the list.
Researchers found New Zealand has 37.72 doctors per 10,000 people and an estimated clinical depression rate of 3.8%.
By comparison, Australia’s warmer and drier climate, with an average temperature of 22.05C and annual rainfall of 534mm, contributed to its lower overall risk score.
However, despite having more doctors available, 42.28 per 10,000, Australia reported a higher depression rate, with 4.9% of residents affected.
Hot Springs Spa general manager Aaron Sampson said colder environments can often lead to “bouts of depression”.
“That said, there are many ways to combat seasonal depression with being exposed to heat being a major factor,” he said.
“Heat can trigger those ‘happy’ chemicals in the brain which can lead to a mood lift.”
The exact cause of SAD is unknown, and there is no test to diagnose it, according to the Mental Health Foundation of New Zealand.
Common symptoms include low moods, irritability, reduced energy, tiredness and anxiety.
“Treatment may be as simple as staying out in the sun for a time each day, or it may mean being treated for depression through the winter months,” the foundation’s website says.
The Himalayan nation of Bhutan was found to be most at risk of SAD, followed by Cambodia, then Guyana.
The country least at risk was South Korea, followed by Argentina, then Poland, according to the study.
