While most SAD sufferers experience symptoms during the winter months, a small proportion of people experience symptoms during summers. In fact, about 10% of people with SAD get it “in reverse”. In fact, in countries that are near the equator, summer SAD is more prevalent. Experts aren’t sure why, but the longer days, and increasing heat and humidity may play a role. As with winter SAD, symptoms of summer depression often include loss of appetite, trouble sleeping, depression, weight loss, and anxiety.