An analysis of data from the Norwegian Trøndelag Health Study, combined with information about prescribed and purchased drugs, has revealed that individuals with higher levels of cardiorespiratory fitness had a slightly lower likelihood of using anxiolytics and antidepressants compared to those with lower cardiorespiratory fitness. This trend was particularly noticeable among men and young adults. The study was published in the Journal of Affective Disorders.
Anxiety and depression are two of the most frequent psychiatric disorders in the general population. Anxiety disorder is a mental health condition characterized by excessive and persistent feelings of anxiety, fear, or worry that significantly interfere with daily life and functioning. Depression is a mood disorder characterized by persistent feelings of sadness, hopelessness, and a lack of interest or pleasure in usual activities.
Although the primary treatment for these disorders includes medication and psychotherapy, studies have shown that physical activity can also be an effective treatment for depressive symptoms. The links between physical activity and anxiety symptoms are less clear, but a recent overview of existing studies reported a small beneficial effect of physical activity on anxiety symptoms. However, large-scale studies of this link are few.
Study author Audun Havnen and his colleagues wanted to explore the relationship between cardiorespiratory fitness at one time point and use of anxiolytics and antidepressants (medications used to treat anxiety disorders and depression) over a 10-year period after that point. Cardiorespiratory fitness reflects how well the circulatory, muscular, and respiratory systems provide oxygen during prolonged exercise. Good cardiorespiratory fitness is a needed for higher levels of physical activity, but physical activity may also improve cardiorespiratory fitness in the long term.
Previous studies have reported that individuals with better cardiorespiratory fitness have a reduced risk of depression and also somewhat lower degree of anxiety symptoms. However, these studies were conducted on relatively small samples. Havnen and his colleagues sought to test this link in the long run and on a sample from the general population.
They analyzed data from the Trøndelag Health Study (HUNT). All inhabitants of the Nord-Trøndelag county in Norway aged 20 years and older were invited to participate in the 4 waves of this study that were conducted between 1984 and 2019. This paper analyzed data from the third wave (HUNT3), where 50,810 individuals participated (54.1% of the population of the county) and 32,603 of them provided all the necessary information.
Each citizen of Norway has a unique personal identification number. The researchers used these numbers to obtain data on their purchases of prescribed anxiolytic and antidepressant medication from the Norwegian Prescription database. This database contains data on all medications prescribed to humans and animals in Norway.
The researchers included the data on the first purchase of anxiolytic or antidepressant medication between 3 months after participation in the third wave of HUNT (2006-2008) and January 1st 2018, roughly a 10-year period in their analyses. Cardiorespiratory fitness was estimated using a statistical model based on sex, age, waist circumference, heart rate at rest, and self-reported physical activity.
The results indicated that participants with better cardiorespiratory fitness were less likely to purchase anxiolytic or antidepressant medications. The higher their fitness level, the lower the likelihood of buying these medications. When adjusting for age, participants with high cardiorespiratory fitness were about 16% less likely to buy these medications compared to those with low fitness. After accounting for additional factors like age, gender, education, marital status, etc., the difference reduced to about 8%.
When looking at men and women separately, and after adjusting for age, women with high cardiorespiratory fitness had around 13% lower likelihood of purchasing these medications compared to women with low fitness. For men, this percentage was 21%, reducing to 13% when considering more factors. Likewise, the difference in medication purchase likelihood based on cardiorespiratory fitness was most significant in young adults (26% difference) but not significant in older adults.
“We found that higher levels of cardiorespiratory fitness were associated with lower risk of purchasing anxiolytic or antidepressant medication. Intermediate and high cardiorespiratory fitness tertiles [groups formed by dividing participants into three equal sized groups based on their cardiorespiratory fitness level] were associated with reduced risk of anxiolytics or antidepressant purchase in both women and men, although stronger associations were observed in men, younger adults aged 20 to 29 years and adults aged 30 to 64. This association was not found for older adults (aged 65 or older),” the study authors concluded.
The study makes an important contribution to the scientific understanding of links between physical exercise and mental health. However, it should be noted that one of the factors researchers adjusted for in their analyses were symptoms of depression and anxiety, which are, typically, the primary reason individuals are prescribed anxiolytics or antidepressants. This is likely to have reduced the strength of the observed links in their adjusted statistical models. Additionally, all participants were from a single county in Norway. Studies on different cultures and in different geographies might not yield the same results.
The paper, “Cardiorespiratory fitness and incident use of anxiolytics and antidepressants in adults. A linkage study between HUNT and the Norwegian Prescription Database”, was authored by Audun Havnen, Ekaterina Zotcheva, Ottar Bjerkeset, Xuemei Sui, Linda Ernstsen.