Sedentary behaviors and risk of depression in the Seguimiento Universidad de Navarra cohort : the SUN Project.

Abstract

The study aimed to prospectively examine the association between different sedentary behaviors and the risk of depression. We included 12,691 Spanish

university graduates (mean age: 36.7 year; SD: 11.5), participants of the Se- guimiento Universidad de Navarra cohort (the SUN Project), initially free of

depression who were followed-up for a median of 10.9 years. Based on items

presented in our baseline questionnaire, time spent in four sedentary behav- iors (hours/day) were evaluated: overall sitting time; TV-viewing; computer

use; and driving. Participants were classified as incident cases of depression if

they reported a physician diagnosis of depression in at least one of the follow- up assessments conducted after the first two years of follow-up. Cox regression

models were used to assess the relationship between sedentary behaviors and depression. A total of 560 incident cases of depression were identified during follow-up. We found no significant association between overall sitting time, TV-viewing or driving and risk of depression. On the other hand, computer use was directly associated with the risk of developing depression during the follow-up (p-value for trend = 0.020), with the participants in the highest

quartile of computer use (3.64 to 10 hours/week) having a higher risk of de- veloping depression (HR = 1.33; 95%CI: 1.05-1.70) than those in the lowest

quartile (0 to 0.25 hours/week) after adjusting for potential confounders. Pro- longed use of computer was independently associated with an increased risk of

developing depression among young middle-aged adult university graduates from a Spanish cohort.