Google Searches Help Provide Insight into Seasonal Trends in Mental Illness

These days, the internet is providing more and more helpful insights into health-related information. Recent research led by John Ayers of the University of Southern California helped comb through questions about patterns of mental illness during different seasons.

Using all of Google's search data from 2006 to 2010, they studied searchers for terms including "schizophrenia" "attention deficit/hyperactivity disorder (ADHD)," "bulimia" and "bipolar" in both the United States and Australia. As winter and summer are reversed in the two countries, they expected to find opposite searches during different times of the year. Thus, the data strongly suggests that the winter season increases the number of some depressive disorders.

 "All mental health queries followed seasonal patterns with winter peaks and summer troughs," the researchers write in their study, published in the American Journal of Preventive Medicine. They found that mental health queries in general were 14 percent higher in the winter in the United States and 11 percent higher in the Australian winter.

Both countries searchers for eating disorders, including anorexia and bulimia, and separately, schizophrenia, surged during the winter months; those in the U.S. were 37 percent more likely and Australians were 42 percent more likely to seek information about these disorders during colder weather than during the summer. And compared to summer searches, schizophrenia queries were 37 percent more common in the American winter and 36 percent more frequent during the Australian winter. ADHD queries were also highly seasonal, with 31 percent more winter searches in the United States and 28 percent more in Australia compared to summer months.

Yet searchers for depression and bipolar disorder didn't solicit as many queries at 19 percent more winter searchers for depression in the United States and 22 percent more in Australia for depression and 16 percent more for bipolar disorder in America and 18 percent more for Australia in the winter. The least seasonal disorder was anxiety, which varied by just 7 percent in the United States and 15 percent in Australia between summer and winter months.

Understanding how weather affects illness could help medical professionals in treating various illnesses, according to experts. For instance, drops in vitamin D levels, which rise with more sunlight, can also cause a negative drop in moods for some.

The researchers emphasize that searches for disorders are only queries for more information, and don't necessarily reflect a desire to learn more about a mental illness after a new diagnosis.