For those of us in the Northern Hemisphere, the weather is slowly getting warmer, roof decks are opening, and if you’re struggling to get into a jolly spring mood, you’re not alone. Seasonal Affective Disorder, a type of depression that’s commonly linked to the winter months, also has a summer variant, known as “summer SAD” or “reverse SAD.” This seasonal depression often begins in spring, when the weather and light begin to change and, though it’s far rarer than winter depression and affects less than 1% of people, this still means that millions are suffering.
The clinical picture of summer SAD is “well documented” says Norman Rosenthal, a psychiatrist and author of the recently published Super Mind. However, the details of exactly what causes summer blues are less clear. Rosenthal and his colleague Thomas Wehr, from the US National Institute of Mental Health, first identified winter SAD in 1984 and three years later, had found evidence of its summertime equivalent. But the precise physiology behind the condition is still debated.
Rosenthal says that as the seasons change, our brain physiology adapts from winter mode to the warmer spring weather, and those with summer SAD likely have trouble transitioning. It’s not known exactly which neurotransmitters are affected, but Rosenthal believes those with summer SAD likely struggle with either the light that comes with expanded days, or else the heat.
The symptoms of summer SAD are also more variable. Whereas winter SAD tends to last five months and cause a depressive slump, some people experience summer SAD starting in spring, whereas others only suffer in the warmer months. However, while winter blues creates lethargy, summer SAD causes insomnia and agitation. Suicides peak during spring months and Rosenthal believes the effects of summer SAD, which can involve both mania and depression combined, are partly to blame.
It’s also possible that sociological factors come into play. In winter, there’s a certain comfort in spending days inside watching movies alone, but spring months bring a pressure to be sociable. “When people are out having a good time and you’re sitting all alone, it could be very isolating,” says Rosenthal.
Others can be affected by the focus on body image. “If you don’t look good in a swimsuit, if your weight is not where you want it to be, you could imagine that this would be depressing,” he adds.
Certainly, the notion that spring is a season to look forward to is not shared by all. Rosenthal says that for one of his clients, the light in summer “cuts through her like a knife.”