Google searches for information about several common mental illnesses showed that conditions followed seasonal trends, suggesting mental illness could be more significantly associated with the seasons than originally thought.

Tracking mental illness patterns has always been a challenge for doctors and scientists. Normally, telephone surveys are given to evaluate the minds of respondents. However, this method is limited because participants may be unwilling to talk honestly about their mental health. The method also has high material costs.

Lead investigator of this study, which was published in the American Journal of Preventive Medicine, John W. Ayers, PhD, MA, of the Graduate School of Public Health at San Diego State University explains:

“The Internet is a game changer. By passively monitoring how individuals search online we can figuratively look inside the heads of searchers to understand population mental health patterns.”

The study researchers used Google’s public database of questions, identifying and following mental health questions in Australia and the United States between 2006 and 2010. All questions relating to mental health were recorded and categorized by type of mental illness. The following common conditions were included:

Investigators used advanced mathematical techniques to pinpoint patterns. They found that all mental health searches in both nations were higher in winter than in summer.

The findings revealed that eating disorder searches declined 37% in the summer compared to the winter in the United States, and 42% in summers in Australia. Schizophrenia searches reduced by 37% during U.S. summers and 36% during Australian summers.

With regards to bipolar searches, they declined 16% during U.S. summers, while in Australia they decreased by 17%. ADHD searches dropped by 28% in the U.S. and by 31% in Australia during summer. OCD searches decreased by 18% and 15% respectively.

Suicide searches fell by 24% and 29% during U.S.summers and 17% during the Australian summertime. Anxiety searches showed the smallest change – a reduction of 7% during the summer in the U.S and 15% in Australian summers.

Some health issues like seasonal affective disorder (SAD) are linked to seasonal weather patterns, but the links between seasons and several of the major disorders were surprising.

James Niels Rosenquist, MD, PhD, a psychiatrist at Massachusetts General Hospital, commented, “We didn’t expect to find similar winter peaks and summer troughs for queries involving every specific mental illness or problem we studied, however, the results consistently showed seasonal effects across all conditions – even after adjusting for media trends.”

Ayers concluded:

“It is very exciting to ponder the potential for a universal mental health emollient, like Vitamin D (a metabolite of sun exposure). But it will be years before our findings are linked to serious mental illness and then linked to mechanisms that may be included in treatment and prevention programs,” said Ayers. “Is it biologic, environmental, or social mechanisms explaining universal patterns in mental health information seeking? We don’t know.”

Benjamin Althouse, a doctoral candidate at Johns Hopkins Bloomberg School of Public Health and researcher on the study, concluded, “Our findings can help researchers across the field of mental health generate additional new hypotheses while exploring other trends inexpensively in real-time. For instance, moving forward, we can explore daily patterns in mental health information seeking … maybe even finding a ‘Monday effect.’ The potential is limitless.”

Written by Kelly Fitzgerald