The present study aimed at investigating whether a blend of MBCT and MBSR methods could be successfully utilized to decrease the depression symptoms and improve the QOL in patients with PTSD. As the results showed, veterans participating in the mindfulness-based treatment considerably changed in terms of depression and QOL after the eight intervention sessions. The significant relief in depression symptoms observed in the intervention group was in line with that of the study by Kearney demonstrating the effectiveness of a MBSR program to decrease the depression symptoms and improvement of QOL status in patients with PTSD (
2). It is also in accordance with the studies showed the impact of mindfulness-based intervention on depression symptoms (
14,
18).
Despite lots of commonalities in theory, each of the MBC and MBSR methods has its own specific techniques, including interventions that target anxiety symptoms and the ones preventing the emergence of recurrent episodes of depression (
19). The changes observed in the intervention group could be attributed to several factors resulted from the combination of the two methods.
As mentioned earlier, it seems that comorbidity of PTSD and depression could be best explained by an underlying stress factor or a feature of mixed PTSD and depression symptoms (
20). Therefore, it is better that interventions focus on the common elements of both disorders (
21,
22).
For example, patients with PTSD typically report deficits in the metacognitive monitoring of memories and thoughts. These efforts to control the thoughts and mental images related to traumatic events, are experienced in the form of flashbacks, and are similar to an element widely observed in depressive rumination; it consequently leads to thought suppression, avoiding emotional pain, and further pathological loops and symptoms (
23). Mindfulness techniques promote acceptance, and welcome the thoughts and mental images related to traumatic events. This method teaches people how to find a new perspective on the events; hence, it could help the patients with PTSD to effectively manage their intrusive thoughts and feelings (
3,
4,
11). Emotional acceptance by adopting a non-judgmental stance toward mental experiences provide opportunities for emotional regulation and self-management. Furthermore, repeated facing with unpleasant internal states encouraged in this method, is a kind of exposure that removes negative associations (
24).
The MBCT also raises patients' awareness of body reactions and non-verbal behaviors, and helps them regulate their arousal (
25). The skills of emotion regulation achieved by mindfulness trainings such as, breathing exercise, distancing from thoughts and emotions, and being at the present moment help the individuals to overcome mood dysregulation and stress via alternative methods they learn.
According to the current study results, the treatment significantly improved some dimensions of the patients' QOL. Chronicity is the dimension greatly influences patient's performance over time. As Steele stated, "Promotion of daily life functioning involves decreasing or eliminating debilitating symptoms of depression, anxiety, and PTSD" (
26). Therefore, as the current study results showed, the intervention group significantly improved in terms of two subscales of QOL, namely general health and social functioning, a finding in line with those of the studies reporting the positive relationship of mindfulness with psychological well-being and improvement of communication and participation (
27). On the contrary, there was no significant change in functional impairment caused by PTSD assessed by subscales related to role limitations due to physical and psychological problems, and have an important role on the patients' QOL (
28).
It can be concluded that, since the present study was cross sectional, it was not adequate to overcome such durable and stable situations caused by the chronic nature of the disorder or the long-term use of medications.
Finally, it was the first study examining the effectiveness of a combined method to reduce depression symptoms comorbid with PTSD in Iranian combat veterans. The current study results suggested that the changes observed in the patients' psychological symptoms can be attributed to addressing their multiple symptoms at the same time. In complex conditions, such as chronic and comorbid mood and anxiety disorders, treatments should be comprehensive and multifaceted, and tailored according to the client's specific needs and impairments. Due to the large number of imposed war's veterans in Iran, as well as veterans affected by war all around the world with disorders similar to those of the participants of the present study, it seems that the combined MBCT and MBSR methods can help to relive them from their signs and symptoms and transcend their lives.
About the application of the present study findings, it should be noted that in psychiatric nursing, effective interventions for mental illnesses are considerable issues. Mindfulness approaches are innovative treatment modalities in health care that have significant implications for such clinical populations in various contexts such as hospitals and day centers and can be used by psychologists, nurses, and other mental health professionals especially the ones that work at veterans counseling centers (
29).
5.1. Limitations
Since, it was the first time that the present combined method was evaluated, it would was advisable that this method be applied in a design using three groups rather than MBCT and MBSR alone. Another limitation of the study was that due to the limited number of participants, they were not matched based on factors such as severity and duration of PTSD. It was recommended to consider such issues in subsequent studies.