Ecological momentary assessment of mood and physical activity in people with depression

Background
: This study aimed to examine temporal associations between physical activity and subsequent mood in people with moderate to severe depression.

Methods
: The study used ecological momentary assessment to associate mood, measured via text messaging twice daily for five days, using a 10-point Likert scale, with objectively measured physical activity (accelerometer data) in people with moderate-to-severe depression. Multilevel regression models were used to explore the relationship between physical activity undertaken at different intensities over the previous one and three hours, and subsequent affect score. A total of 388 paired data points were collected from 43 participants.

Results
: There was no association between minutes of moderate-vigorous physical activity in the previous hour and subsequent affect score (which we had hypothesised). However, exploratory analyses found a significant relationship between affect and combined physical activity in the previous hour (β1 coefficient = 0.023, p = 0.037).

Limitations
: Periods of moderate-vigorous activity were infrequent, reducing the statistical power for analysing associations with this intensity of activity. Only one dimension of mood was sampled.

Conclusions
: The data suggest that, in people with moderate-to-severe depression, time spent engaging in any intensity of physical activity was significantly associated with subsequent mood. Further research is needed to more clearly define the dynamics of the relationship between physical activity and low mood. This will aid identification of optimal prescription criteria for physical activity in people with depression.