This study examined the effects of UP on three common factors and specific cognitive and behavioral sleep-related variables in a sample with mixed chronic insomnia and emotional disorders, using a single-case experimental across-subjects design.
The results obtained using the mixed model analysis showed a significant reduction in BIS and a significant increase in BAS from pre-treatment to post-treatment. These results indicate that treatment with UP improved both dimensions of temperament. Targeting underlying temperamental processes of emotional disorders is one of the goals of UP (
52). One previous study demonstrated that although UP has a modest to moderate effect on BIS/BAS, these changes were not maintained at a 6-month follow-up (
52). Another study (
53) on an Iranian population investigated the effects of UP on BIS in 3 women with GAD using a single-case experimental design, showed overall improvement percentage of 21.75 for 3 patients. In general, the findings regarding the effects of psychological treatments on temperament are mixed. Some studies have shown that even though temperamental variables reduce during treatment, the difference between treatment and control groups increases over time (
54). Moreover, previous studies have indicated that changes in temperamental variables, such as positive affect, are related to the dosage of medication (
55). Thus, in contrast with traditional concepts, various studies have shown that temperament may change over time and in response to treatment. However, it seems that further research is needed to determine specific factors affecting temperament (
52). The results of the current study regarding changes in temperamental dimensions (especially the improvement of BIS scores from post-treatment to follow-up) are congruent with the studies that have proven that changes in temperament increase over time.
Another result of this study was that anxiety sensitivity reduced significantly from baseline to post-treatment. Although, according to visual inspection, different modules of UP were important in reducing AS, the most level of reduction occurred after module 6 (i.e. interoceptive exposure) for a half of the participants. Interoceptive exposure is a behavioral intervention that is known as a strategy to reduce anxiety sensitivity by targeting anxiety associated with physical sensations (
56). Studies have indicated that interoceptive exposure is effective in reducing anxiety and depressive symptoms (
57). In addition, interoceptive exposure has an indirect effect on insomnia symptoms via reducing anxiety sensitivity (
58). In general, the effects of UP on reducing anxiety sensitivity in the current sample may be attributed to different modules, especially module 6 which is specifically designed to target physical sensations.
Significant reductions in emotion dysregulation were observed from baseline to post-treatment. The results of the current study are congruent with those of the previous studies that have proven the efficacy of UP on improving emotion regulation difficulties (
27,
53,
59,
60). Emotion regulation difficulties are a risk factor for insomnia even after controlling anxiety and depression (
61). UP targets highly negative reactivity to emotions via identification of maladaptive responses to emotions and development of more effective strategies regarding the management of emotional experiences (
25). With regard to visual inspection data, two modules of UP may be more accountable for the observed changes. It seems that module 2 via increasing patients’ awareness of functional nature of emotions and components of emotional experiences and module 3 through educating mindfulness skills to accept emotions (
34) play a more significant role in emotion regulation. Given that difficulties in emotion regulation may moderate the relationship between insomnia and psychiatric problems, interventions (such as UP) that target emotion dysregulation may enhance current treatments of insomnia (
61).
Regarding dysfunctional sleep-related beliefs and behaviors, the results obtained by the present study showed that DBAS and SRBQ scores reduced significantly from baseline to post-treatment. Previous research has demonstrated that insomniac patients have more catastrophes about the consequences of sleep loss and probability overestimation of the occurrence of these consequences in comparison with good sleepers (
62). In the present study, the most obvious reduction in DBAS for most participants occurred after module 4 (i.e. cognitive restructuring). Cognitive restructuring as a major module of UP increases thought flexibility in response to emotional experiences. In this module, automatic appraisals and two common cognitive errors are discussed (
34). The efficacy of cognitive restructuring as a standalone therapeutic component in improving sleep difficulties has been demonstrated previously (
63). Although cognitive restructuring may be a more important module in reducing DBAS scores in the present study, previous studies have indicated that behavioral interventions also have a significant effect on dysfunctional beliefs about sleep (
64). Thus, the effects of UP on reducing dysfunctional beliefs specific to sleep may be attributed to both cognitive and behavioral modules of UP.
Insomniac patients, similar to patients with emotional disorders, may be involved in specific safety behaviors (
65). Studies have shown that sleep-related safety behaviors are associated with insomnia severity even in patients with depressive and anxiety disorders (
8). Many modules of UP may contribute to the reduction of sleep-related safety behaviors. In the current study, the most reduction in SRBQ scores was observed after modules 5 and 7. In insomniac patients, going to bed earlier, staying in bed despite inability to sleep, napping during the day, avoidance of, or reduction in, physical activity during the day, and using alcohol to facilitate sleeping can be conceptualized as specific sleep-related safety behaviors that disrupt sleep hemostat and perpetuate insomnia (
66). Like avoidances and emotion-driven behaviors specific to emotional disorders, these sleep-related safety behaviors can also be targeted in the fifth module. Moreover, avoidances and emotion-driven behaviors related to sleep can be graded in a hierarchy according to their difficulty, and then be exposed similar to those in emotional disorders in module 7. However, similar to cognitions, different modules of UP are important in reducing safety behaviors, which is not unexpected considering the interaction between cognition, emotion, and behavior.
The current study had a number of limitations that should be addressed in future studies. This preliminary study included a sample of only six patients with mixed insomnia and emotional disorders. The small sample size makes it difficult to generalize the study results to a larger group of the population. Given the study’s small sample size, it is important for future studies to extend these findings to larger samples to obtain more precise conclusions about the effects of UP on transdiagnostic and specific variables. In addition, the treatment sessions were delivered by only one therapist that limits the generalizability of the results to different therapists. Thus, replication of the current study with different therapists would also be beneficial. Although the multiple baseline design controls factors such as time, it is not possible to specify with confidence whether the improvements were due to identified UP components. Future research would benefit from the inclusion of a control group to facilitate comparison of the effects of treatment with those of nonspecific factors. Evaluation of the intervention with a randomized control design to compare the efficacy of treatment with other common treatments for patients with mixed insomnia and emotional disorders is a necessary next step. This study focused on the evaluation of temperament using BIS/BAS. Although there is an empirical overlap between different temperamental constructs, the results of the current study on temperamental dimensions may be limited to this specific measure. Future work might replicate the current study by administering varied measures to assess and include different temperamental constructs. Finally, longer-term follow-up assessment with 6 or 12 months intervals may be beneficial for assessing the durability and stability of the therapeutic effects.
5.1. Conclusions
The current study marks the first evaluation of the effects of the UP on transdiagnostic and specific factors in a sample with mixed insomnia and emotional disorders and highlights a promising way to deliver UP to reduce vulnerability among this specific population. The findings of the present study have important implications for the clinicians seeking to provide cost-effective interventions for patients suffering from both insomnia and emotional disorders. These results indicate that even in a small sample, UP produced durable and meaningful changes in underlying variables contributing to comorbid insomnia and emotional disorders. Further studies with larger sample sizes and controlled clinical design are needed to evaluate the effects of the UP on transdiagnostic and specific variables in patients with primary and comorbid insomnia.