Sleep, affect and depression: How to tie them together?
background Sleep and mood appear closely tied together, yet there is little known about the character and directionality of this relationship.
aim To characterise the association between self-report sleep and daytime affect prospectively and ambulatory, allowing for cause-and- effect interference; to examine whether thisassociation is moderated by depressive symptomatology in a general population sample.
method In a sample of 621 female participants, positive (pa) and negative affect (na) was assessed using the Experience Sampling Method for 5 consecutive days; subjective sleep was jointly assessed by means of morning and evening questionnaires. Depressive symptomatology was estimated by the scl-90.
results Results showed a significant association between subjective sleep quality and both pa and na (in expected direction), which was of greatest magnitude between sleep quality and pa in women who scored higher on depressive symptoms. There was no significant association between self-report sleep latency and pa, but sleep latency was significantly associated with na in women who expressed higher depression scores.
conclusion These findings tentatively suggest distinct interrelations for different aspects of self-report sleep and daily ambulatory affect which may be moderated by depressive symptoms. Further analysis will focus on the question of directionality of sleep-mood relationships.