According to the findings, the PST program was able to improve the psychological well-being of the patients and changes were maintained until the follow-up stage. In line with our findings, the results of Hirai et al. (
12) and Tsuchiya et al. (
18) suggest the effectiveness of problem-solving therapy in helping patients with breast cancer and patients with lymphedema symptoms to cope with the diseases, and changing their negative beliefs during the therapy procedure. Contrary to the findings of the present study, the results of Mayer et al. suggest the effectiveness of PST to increase psychological well-being of patients suffering from advanced cancer, although it was beneficial in improving the quality of life of patients (
19). Due to the fact that in the PST program, there are techniques to improve psychological health including skills for detecting negative self-proclaimed thoughts and challenging them, setting goals for improving self-care is important. Moreover, positive physical activities and successful problem-solving techniques in the “mind’s eye” are recommended, which lead to creating feelings of optimism and self-sufficiency (
14). Therefore, it seems that PST improves the psychological well-being through affecting the mentioned cases. The findings of this study are also aligned with studies of Lyons et al. (
20), and Hegel et al. (
21), which suggest that PST is effective in coping strategies and improvement in patients with functional limitations and health-related behaviors. This therapy causes fundamental changes in the beliefs, attitudes, feelings, thoughts, and emotions of the patient. For this reason, the patient would innovate adaptive ways in facing life stressors. These techniques help patients to become conscious towards their emotional stresses, release their past emotional patterns, and develop the new emotion of mental and physical inhibition.
The scale we used (Ryff's questionnaire) assesses dimensions such as autonomy, environmental mastery, personal growth, self-acceptance, positive relation with others, and purpose of life. Although few studies have been conducted on the effects of PST on subscales of psychological well-being, findings of other similar studies are aligned with those of the present study. In the same way, studies by ForghaniTorfi et al. (
22) and Heidarianfard et al. (
23) suggest that cognitive behavioral therapy has a significant role in increasing the autonomy among students. Furthermore, findings of Isazadegan et al. suggest that cognitive behavioral therapy is effective in increasing the self-efficacy and environment dominance in obese women (
24). The findings of the current research also agree with those of Modares et al., confirming the effectiveness of teaching problem-solving skill on interpersonal communications among midwives (
25). Based on the findings of this study, Seyedmoharrami et al. (
26) and Omrani et al. (
27) suggest the effectiveness of cognitive behavioral therapy on the aspects of achievement motivation and purposefulness. Also, in line with our findings, Moatari et al. (
28) reported the effectiveness of problem-solving in undergraduate students, and results of the study conducted by Bayat et al. (
29), confirming the role of cognitive behavioral therapy on the subscale of self-acceptance among children. It seems that PST program in the present study was able to provide an opportunity for patterning from successful behaviors, using emotional interactions among the patient group and psychological skills training, and increased resistance to social pressures among the patients. In the course of problem-solving therapy, the necessary skills for solving disease-related problems are acquired, positive thinking strategies are taught, and self-awareness is achieved. Therefore, our findings lead to an increase in purposefulness and self-acceptance. On the other hand, the program, through affecting the attitudes and false beliefs, leads to an improvement in social skills among the patients and their satisfaction in meeting their physical, psychological, and spiritual needs. Therefore, these cases have successfully improved the psychological well-being among the participants.
Considering the fact that breast cancer can lead to dissatisfaction and experiencing various negative emotions, and this causes lack of acceptance of condition, declined health potential and quality of life, and sometimes re-hospitalization and premature death (
30), and due to the fact that life expectancy in women with breast cancer is increasing through advanced diagnosis and treatment methods (
31), it is crucial to adopt measures for controlling the disease complications and improving the psychological well-being of the patients. Applying this therapy to improve the psychological well-being helps to reduce the risk of possible occurrence of mental disorders among these women. As mentioned above, it is crucial to provide breast cancer hospitals or specialty hospitals with counselors, so that patients benefit from psychological counseling as well as medical attention. Moreover, it is required to equip facilities to investigate psychological problems and help researches to improve the health of society. Novelty and advantage of the study is due to the fact that this is the first organized psychological research on the effect of an intervention on women's psychological well-being with breast cancer in Iran.