1. Introduction
ccording to various studies, Cognitive-Behavioral Therapy (CBT) is used for treating chronic insomnia; however, the adherence rate is not very high [9, 10, 11]. A reason for decreased adherence to treatment can be attributed to an individual’s perception of the disease. When a subject receives effective treatment, they will observe a decrease in the perception of the disease and an increase in adherence to it [14]. The perception of the disease includes 5 components of identity, outcome, timeline, treatment/control, and cause [15]. Various studies indicated that the components of disease perception were significantly related to the effectiveness, outcome, and follow-up of treatment in various chronic conditions [22, 23, 24, 25, 26]. Therefore, when CBT reduces the perception of the disease in chronic insomnia, it will increase the effectiveness of treatment and adherence to it. The current study aimed to compare the effects of CBT, pharmacotherapy, and waiting list on sleep efficiency index and disease perception. 
2. Materials and Methods
This was a quasi-experimental study with pre-test, post-test, quarterly follow-up, and a control group. The study participants included 74 patients (43 females) who were selected by purposive sampling method and were divided into 3 groups; CBT, pharmacotherapy, and waiting list. The research instrument included a Persian version of the short form of the Brief Illness Perception Questionnaire and Sleep Efficiency Index to measure the cognitive and emotional representation of patients and the efficiency index to measure the rate of sleep efficiency. Patients were sampled from a psychiatric clinic and a health center in Kashan City, Iran, and randomly assigned to 3 study groups. After all, patients were trained on how to complete the research tool, they were assessed in 3 stages. The CBT group received eight sessions of 30 to 120 minutes of psychotherapy. Moreover, the pharmacotherapy group received 10 mg of zolpidem tablets per night. The obtained data were analyzed using repeated-measures Analysis of Variance (ANOVA) and Bonferroni Post Hoc test.
3. Results
MANCOVA was used to compare the effects of CBT on chronic insomnia and pharmacotherapy on perceiving illness and sleep efficiency. After the assumptions of MANCOVA were met, the Wilks’ Lambda test was used to examine the potential differences between the evaluation stages and the group interaction and the evaluation stage (Table 1).


The significance of Wilke’s Lambda test suggested a significant difference between at least 2 study groups in one of the evaluation stages; there was a significant relationship between the evaluation and interaction stages of the group effect and the evaluation stages.
The final results of Tables 2 and 3 suggested that the CBT group, in the post-treatment and follow-up stages was significantly superior to the waiting list group in terms of efficiency in the consequences of disease perception and sleep efficiency.




There was no significant difference between CBT and pharmacotherapy in the post-treatment phase respecting effectiveness on disease perception and sleep efficiency. However, patients in the CBT group experienced a significant improvement in the three-month follow-up phase, compared to patients receiving zolpidem 10 mg. Additionally, there was no significant difference between the pharmacotherapy group and the waiting list at the quarterly follow-up stage.
4. Discussion and Conclusion
The present study findings indicated that CBT and pharmacotherapy (zolpidem 10 mg) can significantly reduce the severity of disease perception in patients in addition to a significant increase in sleep efficiency index. Furthermore, the therapeutic achievements of the CBT group continued even up to three months after the end of treatment; however, the patients in the pharmacotherapy group, after gradual discontinuation of the drug, gradually presented an increase in disease perception and decreased sleep efficiency. The passage of time could not lead to a significant change in the scores of the waiting list group in the pre-treatment, post-treatment, and quarterly follow-up stages. Even the group’s quarterly follow-up scores had deteriorated somewhat, compared to the pre-treatment phase.
Patients receiving CBT have learned to reduce the hours of sleep in favor of its quality and to eliminate the conditioned association between sleep-related stimuli and the inability to fall asleep and hyperexcitability [31]. In addition to improving sleep hygiene, patients in this group did not have much opportunity to engage in rumination and anxiety due to the implementation of the treatment protocol, which led to a decrease in their level of arousal [32, 33, 34]. In such cases, their perception of control and treatability increased. After performing the technique of delaying worry and rumination, these patients manifested a decrease in the severity of anxiety; the explored patients’ perception of the signs and symptoms of the disease also decreased.
The examined patients in the drug treatment group, after experiencing a reduction in insomnia symptoms, could experience high scores on sleep efficiency and a decrease in the severity of disease perception; a process that continued only until the post-treatment stage [16, 28, 37]. Therefore, the perception of the disease is among the components that with successful treatment can reduce its severity in the tissue of chronic insomnia.

Ethical Considerations
Compliance with ethical guidelines
This study was approved by the Ethics Committee of Kharazmi University of Tehran (Code: IR.KHU.REC.1398.008). All the researchers of the present study were obliged to follow the Helsinki Declaration at all stages of the research.

Funding
The paper was extracted from the PhD. dissertation of the first author at the Department of Clinical Psychology, Faculty of Psychology & Educational Sciences, Kharazmi University. 

Authors' contributions
All authors participated in the preparation of this article and met the standard writing criteria based on the recommendations of the International Committee of Medical Journal Publishers (ICMJE).

Conflicts of interest
The authors declared no conflicts of interest.

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