Insomnia is a major public health problem and can, if untreated, lead to a range of physical and mental health problems, such as hypertension, obesity, cardiovascular disease, depression and anxiety disorders (1–3). Sleep problems are especially common among university students (4, 5). A systematic review of the prevalence of insomnia in 16,748 university students found a weighted mean of 18.5% (ranging from 9.4–38.2%), which was substantially higher than in the general population at 7.4% (6).
The increased prevalence of insomnia may be attributed to numerous challenges in the lives of students. University students face high expectations of their education and future careers, have to develop greater personal independence, and face the challenge of balancing social activities, part-time jobs, and self-directed studying, all while contending with financial pressure due to rising tuition fees and living expenses (7). These generally conflicting demands can lead to excess stress among students, making them a high-risk population for both sleep disturbances and mental health complaints (8). Moreover, university students are in an age group that is particularly vulnerable to the onset of psychopathology (9).
A growing body of literature supports the effectiveness of psychological interventions for insomnia, especially cognitive behavioral therapy for insomnia (CBT-I). During CBT-I, patients learn to identify and modify maladaptive thoughts, attitudes, and behaviors, by utilizing psychoeducation, cognitive restructuring, stimulus control, sleep restriction, and relaxation techniques. It has been shown effective in both individual and group face-to-face formats as well as in online formats (10–12), and even for those with subthreshold insomnia (13). About 70–80% of people with insomnia benefit from CBT-I (14). Furthermore, sleep interventions including CBT-I show smaller effect sizes in students than in the general adult population (10, 15, 16). Chandler et al. almost exclusively included CBT-I studies and found a moderate effect size (d = 0.55), while Saruhanjan et al. and Kodsi et al. included more studies with different types of sleep interventions, such as sleep education and relaxation training, and found moderate effects on sleep, with effect estimates of 0.61 and 0.51, respectively. A possible explanation for the smaller effect size in students may be that several interrelated factors are especially relevant in the lives of students that are insufficiently addressed in current interventions. For instance, issues relevant to students include perfectionism, stress-sleep reactivity, poor psychological flexibility and coping skills, which are known to contribute to the development and maintenance of sleep problems (5, 17–19) and may have to be emphasized more in a student population. Students may require a tailored approach that considers their specific challenges and circumstances. Interventions targeting multiple behaviors and skills simultaneously may therefore be more effective than single-component treatments to promote better sleep among students.
A promising add-on to CBT-I is mindfulness-based interventions. Mindfulness is a practice aiming to direct an individual’s attention to the present moment without judgement and increase awareness of internal and external experiences (20). It is used to decrease stress and increase mental well-being through exercises such as breath regulation and body-scan meditation (21). A recent meta-analysis of seven RCT’s showed that mindfulness-based stress reduction significantly improved sleep quality, depression, and anxiety among adult insomnia patients (22). Another study among adolescent girls examined the effectiveness of a multi-component mindfulness-based group intervention and found that the intervention was feasible and resulted in moderate improvements in subjective sleep (23). Therefore, in order to tackle the stress-related factors mentioned above that are intertwined with the lives of students, mindfulness-based techniques might be a fruitful add-on to sleep interventions.
A brief group multi-component sleep-mood intervention combining CBT-I and mindfulness practices with lifestyle components, the Sleep Mood Intervention: Live Effectively (SMILE) intervention, was developed to target sleep and mood in university students, taking into account the needs of this target group. The objective of the present study was to assess the effectiveness of the SMILE intervention in university students with sleep complaints. The primary outcome was insomnia severity. The secondary outcomes were symptoms of depression, anxiety and quality of life. Given the close relationship between sleep and mental health, we hypothesized that SMILE improves all outcomes. Secondly, we explored the mechanisms of change, namely whether the treatment effect on insomnia was mediated by dysfunctional beliefs about sleep and levels of pre-sleep arousal. Both are factors that have been previously assessed as mediators in other intervention studies on sleep outcomes (24).