Other research projects
Research: Sleep satisfaction in depression
Many of the sleep studies in this field have focused on how objective measures illustrate disturbed sleep in depression. Typically this has been undertaken with sleep EEG, which has shown that depressed individuals take longer to get to sleep, wake more often throughout the night (and for longer periods), wake earlier than desired, and generally sleep less than those not depressed. These studies also show that rapid-eye movement (REM) sleep is altered; depressed people tend to enter REM sleep earlier during the sleep episode, and spend more time in REM sleep throughout the night. However, in my PhD, I felt that subjective factors had been overlooked. This work was undertaken in collaboration with Professor David Baldwin (University of Southampton) and Dr Hannie van Hooff (now at University of Amsterdam).
What we did
We explored the relationship between sleep and depression (as well as anxiety) across three empirical studies and two reviews. The state of research regarding the relationship between sleep and depression was reported in our review Mayers & Baldwin, 2006. The effect that antidepressants have on sleep may also be a factor in this relationship. Some antidepressants appear to promote sleep, while others have been observed to disrupt sleep. We explored this in our review Mayers & Baldwin, 2005. Published in Human Psychopharmacology Clinical and Experimental, this paper has been cited widely over several years (see Publications page).
Subjective perceptions of sleep satisfaction were compared to perceived sleep timing in a series of studies focusing on depressed patients, healthy controls, and first-degree relatives. In the first study Mayers, van Hooff & Baldwin (2003a), Twenty depressed patients were compared to 20 healthy controls. We found that the depressed group reported significantly poorer sleep satisfaction than controls, even though they did not differ from controls on sleep timing perceptions. Our second study replicated these findings, but also explored whether sleep perceptions in depression were expressed in a similar way by the nearest relatives. We found that the immediate relatives of depressed patients reported sleep in much the same way as the depressed individual, while there were no such similarities between the healthy controls and their relatives. Furthermore, reports of poor sleep by the relatives of depressed patients were associated with reports of poorer mood, while poorer sleep perceptions in the control group (and their relatives) were more likely to be related to feelings of weariness. Further details about this study can be found in Mayers, van Hooff & Baldwin (2003b). In our third study, we specifically differentiated perceptions of sleep timing and sleep satisfaction in relation to reports of anxiety and depression, using samples drawn from Depression Alliance UK (n = 46) and university students (n = 52). Using independent one-way ANOVAs and multiple regression, we found that variance in sleep timing perceptions were more likely to be associated with anxiety, than depression. Meanwhile, variance in perceptions of sleep satisfaction was more likely to be explained by depressive symptoms. Further details about this study can be found in Mayers, Grabau, Campbell & Baldwin (2009).