This study aimed to determine the effectiveness of ACT on positive and negative symptoms and emotion regulation in patients with SSD. It was performed for the first time as a single-case study on five participant in Razi Educational and Therapeutic Psychiatric Center, and the results showed the effectiveness of ACT in reducing psychotic symptoms and improving emotion regulation. Although these results are inconclusive, and many factors may play a role in the patient's recovery (including TAU), ACT is an effective therapeutic intervention to provide psychological services to patients with SSD. Also, differences between the PANSS and DERS scores in the intervention and follow-up phases indicated small to medium effect sizes.
Considering the mean PANSS scores in the baseline, intervention, and follow-up phases, the rate of psychotic symptoms decreased in patients to some extent. Although the purpose of ACT is not to reduce the symptoms of psychosis, these changes may be one of its outcomes (
46). Regarding the relationship between experiential avoidance and hallucinations (
26) and delusions (
47), it seems that ACT can change the patient's relationship with the symptoms rather than the symptoms themselves. The results are consistent with the findings of study by Yildiz (
48). Since SSD patients suffer from symptoms, such as depression, anxiety, and hallucinations, it seems that ACT can first reduce the psychological stress of hallucinations and then decrease the symptoms of psychosis and emotional dysregulation.
Consistent with the findings of the present study, Shawyer et al. (
26) found that ACT had moderate effects on psychotic symptoms. Considering the effect of ACT on stress caused by hallucinations, it seems that ACT improves the patient's emotion regulation after reducing stress, which is effective in reducing their psychotic symptoms. In the present study, ACT had small and moderate effects on psychosis symptoms and emotion regulation, respectively by reducing stress caused by psychotic symptoms and emotion dysregulation; nonetheless, this study had a single-case design.
Regarding the decline in the mean DERS scores, the results of the present study are consistent with the findings of previous studies conducted by White et al. (
23), Louise et al. (
49), and Villatte et al. (
50), which suggested a reduction in emotional dysregulation caused by psychosis and acceptance of emotions. The ACT possibly encouraged patients to move toward their life values and goals by helping them accept their painful mental experiences; this played an important role in their emotional functioning. According to these findings, ACT was effective in improving the patients’ emotional regulation.
Based on the scores of the first, second, fourth, and fifth participants in the intervention phase compared to the baseline phase, the scores of psychotic symptoms and emotional dysregulation decreased compared to the baseline phase, which shows the low to moderate effectiveness of ACT. Also, the first, third, and fourth participants obtained low scores on PANSS in the follow-up, and the scores of the second and fifth participants showed a moderate effect size; in other words, ACT had small and moderate effects on the symptoms of psychosis. Considering the relationship between anxiety reduction and cognitive defusion (
51), it seems that ACT, by using failure strategies, such as conscious observation of psychiatric experiences, reduces the stress caused by the symptoms and then diminishes psychotic symptoms and improves emotion regulation. Although it is not clear if cognitive defusion is effective in reducing the symptoms, this study showed that ACT could offer effective strategies, such as acceptance and non-judgment, distancing, and isolation from psychotic experiences.
Tyrberg et al. (
52) and White et al. (
23) showed that people with psychosis can follow their personal values by attending ACT sessions. However, the average number of ACT sessions in their study was two sessions, while in the present study, 15 ACT sessions were held. Based on the findings, although all participants experienced psychotic symptoms constantly, commitment to therapeutic homework appeared to be effective in reducing psychotic symptoms and improving emotion regulation. By using mindfulness and emotion acceptance, ACT seems to help patients view their treatment as a rewarding experience; this result is consistent with the findings of a study by Spidel et al. (
27). This result is of great significance owing to the role of emotion regulation in an individual’s functioning and psychotic symptoms (
31). Although ACT may be helpful for SSD patients, any conclusions regarding the effectiveness of ACT for this group should be made with caution. Therefore, further research is needed to replicate our findings using a larger sample size and group therapy and compare the findings with a control group.
The most important limitation of the present study is that due to the COVID-19 epidemic, sampling and testing were performed under strict observance of health protocols. Therefore, it is recommended to perform ACT in a group for people with SSD in psychiatric and mental health centers in case of reduction of the coronavirus disease epidemic. Also, not checking negative symptoms, small sample size, and limited generalizability of the findings made it difficult for us to reach definite conclusions. On the other hand, the strengths of this study include exclusive, patient-centered treatment, collaboration with other therapists (e.g., psychiatrists, psychologists, nurses, social workers and counsellors), and initiation of treatment after control of acute psychotic symptom with medications.
5.1. Conclusions
The application of the ACT may be an appropriate and valuable additive for reducing the psychotic symptoms and improving the emotional regulation of the people with schizophrenia in psychiatric and mental health centers. It can play a valuable role in the mental health of SSD patients by changing their attitude towards psychotic symptoms and improving their emotion regulation. Replication of this study in the future can provide promising results for the establishment of ACT in psychiatric wards. It seems that ACT is a suitable option for psychologists, psychiatrists, nurses, and paramedics working, counsellors, mental health experts and other clinical professionals working in Educational, Therapeutic and Rehabilitation Psychiatric Centers.
5.2. Highlights
The ACT plays an effective role in reducing the positive and negative symptoms of SSD patients and improving their emotional regulation.