Subjective and Objective Measures of Activity in Depressed and Non-depressed Individuals in Everyday Life

Reduced physical activity is considered a key feature of major depressive disorder (MDD). However, research directly comparing non-depressed controls and patients yielded mixed findings. In contrast to most previous research, this study compared objective as well as subjective activity levels of individuals with MDD with non-depressed controls and used an ambulatory assessment method. Moreover, we investigated whether objective and subjective measures of activity could predict mood. On two consecutive days, physical activity of 35 MDD patients and 36 non-depressed control participants were assessed objectively using an accelerometer and subjectively with hourly ecological momentary assessments. During the same assessment, participants mood was monitored. No significant differences between MDD patients and control participants in objective and most of the subjective activity measures were observed. We found significant associations between objective and subjective measures of activity in non-depressed as well as in MDD patients. Objective but not subjective measures of activity predicted subsequent mood. Our results support the notion that the association between MDD and activity level is complex and depends on moderating factors.