The study, which was led by John W. Ayers from the Graduate School of Public Health at San Diego State University, shows that Google searches about mental disorders followed seasonal patterns. According to this research, mental disorders could be more correlated with the seasons than initially believed.
The findings were published in the American Journal of Preventative Medicine. With the help of Google’s public database of queries, the scientists assessed mental health searches in the United States and Australia from 2006 to 2010. Then the researchers grouped the mental conditions, which included attention deficit hyperactivity disorder, anxiety, bipolar disorder, depression, eating disorders like anorexia or bulimia, obsessive-compulsive disorder, schizophrenia and suicidal ideation.
Using mathematical methods to analyze trends, the researchers found that in both the U.S. and Australia, all mental health searches were less frequent in the summer than in the winter. In fact, the pattern seemed to reflect the length of sunlight according to the season.
Searches in the United States on eating disorders were 37 percent lower in the summers in comparison with the winters, while they were 42 percent lower during the summers in Australia. Searches on bipolar disorder were 16 percent lower during American summers and 17 percent lower during Australia ones.
The scientists found search declines during the summers on schizophrenia, ADHD, anxiety and OCD, activity that appeared in both the U.S and Australia. Searches on suicide also declined by 24 and 29 percent in the respective countries.
The findings are interesting because while certain mental conditions -- like seasonal affective disorder -- are known to follow the seasons, it wasn't really known that there could be a seasonal link with other mental conditions, too, researchers noted.
Studying mental illness typically presents a challenge since participants are often reluctant to provide honest answers about mental health, but researchers noted that the Internet offers a great tool that provides anonymity so that researchers can better analyze pervasiveness of mental conditions in the U.S.