A recent study, funded by the Research Council of Finland as part of the Climate Change and Health research program, delves into the connection between changing light levels and fluctuations in mental health. The findings reveal a discernible increase in sick days attributed to depression, anxiety, and sleep disorders during October and November in Finland, contrasting with lower-than-expected absences from June to September. The study, analyzing 636,543 sick leaves due to mental health reasons over 12 years using Kela’s sick leave register, sheds light on the seasonality of mental health issues.
During late autumn, the incidence of sick days nearly doubles compared to summer and is about a quarter higher than in early autumn. Conversely, manic episodes associated with bipolar disorder manifest more frequently during spring and summer, coinciding with increased daylight hours, and less frequently during darker periods.
Professor Marianna Virtanen from the University of Eastern Finland emphasizes the potential impact on workplace dynamics and healthcare services, particularly during autumn when depression, anxiety, and sleep disorder-related absences peak. Virtanen suggests exploring alternative explanations, such as heightened psychosocial stress in the workplace during autumn, contributing to the surge in sick leaves.
As climate change is anticipated to bring darker winters and brighter summers to Finland, the study posits potential implications for mental health. Darker winters may intensify depression, anxiety, and sleep disorders, while brighter summers could alleviate these conditions. In the case of bipolar disorder, darker winters might alleviate manic symptoms, while brighter summers could exacerbate them. The study underscores the need to consider environmental factors, such as changing light levels, in understanding and addressing mental health challenges, as climate-related shifts may influence the prevalence and seasonality of these conditions in the future.
