Schizophrenia is recognized as one of the twenty leading causes of disability worldwide. This disorder has significant health, social, occupational, and economic consequences. These consequences can be the result of the early onset of the disorder and its severe and persistent symptoms (
1). The findings of Shinn and Viron suggest that schizophrenia is associated with cognitive impairments, including executive dysfunction. In addition, individuals with schizophrenia, who are stigmatized by society, have insufficient insight (
2). Insight refers to a person’s ability to diagnose (psychological insight) and accept mental illness (emotional insight). Therefore, a lack of insight means a lack of awareness of one’s mental illness (
3). However, impaired insight is more commonly seen as a hallmark of schizophrenia. A significant proportion of patients with schizophrenia have poor or no insight. Accurate knowledge of the patient’s level of insight can help us gain access to the pathology of the disorder, its prognosis, and aspects of its treatment (
4). Inadequate insight or lack of insight into the disease is a major barrier to treating individuals with schizophrenia. However, giving insight to some individuals with the disease will lead to stability and improvement (
5).
What is certain, however, is that poor insight prevents the treatment of psychosis in the early stages of the disorder (
6). Poor insight into the disease can lead to partial adherence or non-adherence to treatment in a large number of patients with schizophrenia. Non-adherence to treatment is a major risk factor for poor treatment outcomes, such as relapse, readmission, and suicide (
7). Poor medication adherence is a major factor in the recurrence of the disease in individuals with mental disorders. Therefore, supporting drug adherence is an important issue in the recovery and rehabilitation of patients with mental disorders (
8). Based on the evidence, 41 - 53% of patients with schizophrenia have poor drug adherence (
9). However, drug adherence factors in patients with schizophrenia have always been crucial in the treatment and rehabilitation of these patients. However, treatments are not the same in different countries, and no study has been conducted on the factors affecting drug adherence in different mental healthcare settings (
10).
Although pharmacotherapy has been the mainstay of treatment for patients with schizophrenia since the first half of the twentieth century, whether or not a patient accepts medication is crucial in clinical decision-making because it plays an important role in the effectiveness and adherence to treatment (
11). However, despite their effectiveness, a total of 37.5% of the patients on oral antipsychotics and 11.5% of those on long-acting injectables abandoned the treatment (
12).
Accordingly, in recent decades, psychiatry has not only alleviated the symptoms of mental disorders but is also related to the quality of life of these patients, their return to previous functioning, and their well-being. That is, to change the paradigm that has transformed research results into mental illness (
13). Although the evidence for the effectiveness of psychological interventions for schizophrenia (psychotic disorders in general) is increasing, there is still no consensus on the reduction of symptoms by this type of intervention (
14).
Cognitive behavioral therapy (CBT) has been shown to be effective for a wide range of problems, including depression, anxiety disorders, alcohol and drug abuse, marital problems, eating disorders, and severe mental illness. Numerous research studies have shown that this approach leads to a significant improvement in performance and quality of life. Many studies have shown that CBT is as effective as or even more effective than other psychological therapies or psychiatric medications (
15). This treatment for psychosis, along with antipsychotic drugs and routine comprehensive care in the management of schizophrenia, is also recommended (
16). Several international protocols have also recommended and emphasized this treatment approach to schizophrenia as the gold and standard treatment to meet the needs of these patients (
17).
More than 60 randomized controlled trials (RCTs) have examined the effect of CBT on patients with schizophrenia and other psychotic disorders. Although meta-analyses have reported a reduction in a wide range of symptoms, the effect of this therapeutic approach on patients in the early stages of psychosis has been less studied in RCTs. This is important because patients in the early stages of psychosis might have completely different treatment needs than patients with multiple periods and a more prolonged history of illness (
18). However, the average size of the effects reported in recent studies is small and even smaller in studies with more rigorous methodologies (
19).
Although the effectiveness of CBT in schizophrenia has been somewhat proven, there is less evidence for the group form of this therapeutic approach. For example, in a study by Barrowclough et al., the main hypothesis (i.e., the significant improvement of positive symptoms of psychiatric patients by group cognitive behavioral therapy (GCBT) compared to the usual treatment of patients) was not confirmed by the research findings. However, although there was no significant difference between the intervention and control groups in the severity of symptoms or performance or recurrence, the members of the GCBT group reported a decrease in feelings of hopelessness and low self-esteem (
20). However, there are limited empirical studies on the effectiveness of group interventions in individuals with psychosis. The data show that those who are referred to the group intervention program might improve their performance effectively (
21). A clinical trial by Elwyn et al. with a very small sample of five subjects showed that the participants were very satisfied with CBT in the form of group intervention, and their psychotic symptoms were significantly reduced after the group intervention compared to those before the intervention (
22). Generally, some research results confirm that adding a brief psychological intervention to routine care in a psychiatric clinic is an effective way to improve the significant symptoms of schizophrenia (
23).
It seems that taking therapeutic measures in a group manner for patients with schizophrenia is crucial. Since group interventions are more cost-effective, their effectiveness should be analyzed in different cases of mental disorders. Moreover, such interventions can lead to improvements in the treatment of mental disorders. The results of this study can be used in outpatient and inpatient treatment centers to help patients with schizophrenia.