Integrative body–mind–spirit intervention for concurrent sleep and mood disturbances: sleep‐specific daytime functioning mediates sleep and mood improvements
Sleep disturbances and depression co‐occur frequently. It has been shown that the comorbidity of 1‐year sleep problems with major depressive disorder (MDD) and dysthymia is 17.3% (Roth et al., 2006). Moreover, there have been consistent findings that sleep problems are associated strongly with depression, and the relationships between them are reciprocal and interactive (Baglioni et al., 2010; Jansson‐Fröjmark and Lindblom, 2008). Therefore, co‐occurrence of insomnia and depression inevitably increases the disease burden and is associated with greater severities of daytime symptoms and functional impairments, compared to having either condition alone (Romera et al., 2013). Thus, it becomes necessary to examine daytime functioning closely in concurrent sleep and mood disturbances.
Although there has been growing interest in improving individuals’ daily functioning in treatment of comorbid insomnia and depression, the effectiveness is mixed in different intervention modalities. Mind–body intervention performed better in improving sleep quality in comparison to CBT‐I, although both treatments can reduce energy loss and depressive symptoms effectively (Chan et al., 2012). Mindfulness‐based cognitive therapy (MBCT) was found effective in improving physical functioning, emotional role of Health‐Related Quality of Life (HRQoL) and depressive symptoms, but not sleep quality (Britton et al., 2010). In view of these inconsistencies in efficacy, further investigations are required on the clinical relevance of sleep and depression to individuals’ daytime functioning in order to identify stepped care targeting varied populations with sleep and mood problems.
In addition, few studies have looked into the mediators of the relationship between sleep and mood changes, and even fewer in intervention studies. Slavish and Graham‐Engeland (2015) found that rumination mediated the relationship between depressed mood at baseline and sleep quality 2 months later in healthy adults. Using a 30‐day time–series design, Bouwmans et al. (2017) found that fatigue was a mediator between disturbed sleep and next‐day affect in both depressed subjects and healthy individuals, but daytime affect did not contribute to night‐time sleep, and rumination was not a significant mediator. It seems that certain daytime features mediated temporal sleep and mood relations. However, there is still a lack of investigation on wide‐ranging daytime variables in mediating the temporal relationship between sleep and mood following intervention. Such investigations are important for deepening our understanding of interplay of sleep problems and depressive mood.
Our group has developed an I‐BMS intervention, which has been found effective in treating various health conditions (Chan et al., 2006; Sreevani et al., 2013), including sleep disturbances with concurrent depressive symptoms (Ji et al., 2017). I‐BMS intervention is a holistic treatment influenced by Daoism and Buddhism, and incorporates ancient qigong and traditional Chinese medicine practice into modern group therapy (Lee et al., 2009).