Adults with good cardiorespiratory fitness—the ability of the circulatory and respiratory systems to supply oxygen during sustained physical activity—have half the risk of developing symptoms of depression, suggests a study in the Journal of Affective Disorders.
Vincenza Gianfredi, M.D., and colleagues at Maastricht University in The Netherlands analyzed data from 1,730 adults aged 40 to 75 years in The Maastricht Study, a large population-based study that focuses on the development, progression, and complications of type 2 diabetes, although not all participants in the study have the condition. The study measured the participants’ cardiorespiratory fitness at baseline through an exercise test on stationary bicycles. The researchers divided the participants into three groups according to whether they had low, medium, or high cardiorespiratory fitness. Participants completed the Patient Health Questionnaire-9 (PHQ-9), which is used to screen for symptoms of depression, at baseline and during annual follow-ups over five years.
During five years of follow-up, 9.6% of the participants developed clinically relevant symptoms of depression (defined by authors as a score of at least 10 on the PHQ-9). When the researchers compared rates of depressive symptoms among the three groups of participants, they found that compared with participants who had low cardiorespiratory fitness, those with medium or high cardiorespiratory fitness had a 50% lower risk of developing depressive symptoms. This reduced risk was independent of the participants’ current exercise levels. Results remained similar when the researchers excluded participants who were taking antidepressants at baseline and participants who had a lifetime history of major depressive disorder.
“In other words, long-term [moderate to vigorous physical activity]-based interventions or other approaches that lead to increased [physical activity] may be effective in preventing depression so far as they also lead to an improvement in [cardiorespiratory fitness],” Gianfredi and colleagues wrote. “Short-term [moderate to vigorous physical activity] or low-intensity [physical activity] may not be sufficient to prevent clinically relevant depressive symptoms.”
For related information, see the Psychiatric News article “Exercise May Offset Genetic Risk for Depression.”