METHODS
1. Study Design
We conducted a qualitative meta-synthesis to analyze and integrate findings from qualitative studies on the factors influencing medication adherence in individuals with schizophrenia in South Korea. Thematic synthesis, as outlined by Thomas and Harden [
15], was used to synthesize the selected studies. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines [
16].
2. Study Identification
A systematic literature search was conducted to identify qualitative studies on the factors influencing medication adherence among individuals with schizophrenia in South Korea, following the PRISMA guidelines [
16]. The search was performed from November 5 to December 4, 2024, across both international and domestic databases with no restrictions on the publication period. The international databases searched included the Cumulative Index to Nursing and Allied Health (CINAHL), PubMed, and Web of Science, whereas the domestic databases included DBpia, Korea Citation Index (KCI), Korean Studies Information Service System (KISS), KoreaMed, Research Information Sharing Service (RISS), and ScienceON. The search strategy utilized a combination of keywords connected by "AND" and "OR" operators. For the international databases, the search terms were as follows:
• Schizophrenia-related terms: "schizophrenia (MeSH Terms)," "schizophrenia," "schizophren*," "schizoaffective," "schizophrenic*," "psychosis"
• Medication adherence-related terms: "medication adherence (MeSH Terms)," "medication adherence," "medication compliance," "medication persistence," "medication management," "medication therapy," "drug therapy," "drug adherence," "drug compliance," "medication nonadherence," "medication noncompliance," "drug nonadherence," "drug noncompliance"
• Barrier- and facilitator-related terms: "barrier*," "facilitator*," "experience," "factor*," "obstacle*," "perception*," "perspective*"
• Geographical terms: "Korea (MeSH Terms)," "Korea," "Republic of Korea (MeSH Terms)," "Republic of Korea," "South Korea" For domestic databases, the Korean search terms included:
• Mental disorder-related terms: "정신장애" (meaning: mental illness)
• Schizophrenia-related terms: "조현병," "정신분열증," " 정신분열병"(meaning: schizophrenia)
• Medication-related terms: "약물"(meaning: medication)
3. Inclusion and Exclusion Criteria
The selection criteria for this review were as follows: Studies that explored factors influencing medication adherence among Korean adults (aged 19 or older) diagnosed with schizophrenia. The eligible studies employed qualitative research methods, including focus group interviews and thematic or content analyses. The articles were published in English or Korean in either international or domestic peer-reviewed journals, with no restrictions on the publication date. Conversely, studies were excluded if they used research methods other than qualitative approaches, included unpublished works (e.g., dissertations, posters, conference abstracts, or presentations), or lacked an accessible full text.
4. Study Selection
A literature search was conducted by two researchers (EP and SS) who independently screened the articles for duplicates and eligibility. Disagreements were resolved through discussion. The database search initially identified 6,043 studies, of which 2,324 were duplicates. The title and abstract screening of the remaining 3,719 studies excluded 3,694 studies that did not employ qualitative research methods. Full-text reviews of the remaining 25 studies led to the exclusion of 16 studies that did not examine patients with schizophrenia and six that did not focus on medication adherence. Ultimately, three studies were selected. The study selection process is illustrated in
Figure 1.
5. Quality Assessment
Two researchers (EP and SS) independently evaluated the quality of the selected studies using the Critical Appraisal Skills Program (CASP) Qualitative Studies Checklist [
17]. This checklist consists of ten questions assessing key criteria, including a clear statement of research aims, appropriate methodology, research design, recruitment strategy, data collection, researcher-participant relationships, ethical considerations, data analysis, clarity of findings, and overall research value. Because the CASP checklist does not provide explicit guidelines on scoring or setting cutoff points for each criterion, the researchers used a simple "Yes," "No," or "Can't tell" scale for each item. Each study was assessed based on these criteria, and any disagreements were resolved through discussion and mutual agreement between the researchers. All the studies included in the final selection were assessed, and no studies were excluded based on quality.
6. Data Synthesis
This study followed the systematic qualitative synthesis approach outlined by Thomas and Harden [
15]. In the first stage, two researchers (EP and SS) independently analyzed the themes and extracted relevant quotations from the study findings. Researchers repeatedly read the material to categorize it according to its meaning and content. In the second stage, they examined the coded data and categorized them according to similarities, differences, and interrelationships to develop descriptive themes. In the third stage, the researchers synthesized a comprehensive list of themes related to the factors influencing medication adherence in individuals with schizophrenia. From this synthesis, they generated new analytical themes, offering insights that extended beyond previous studies.
DISCUSSION
We conducted a comprehensive qualitative analysis of the factors influencing medication adherence among individuals with schizophrenia using an ecological model as a theoretical framework. Synthesizing the findings of these three studies provides a deeper understanding of the complex and multifaceted nature of medication adherence in this population, which often exhibits low adherence or non-adherence. Based on the principles of the ecological model, the three distinct barriers and facilitators affecting medication adherence were identified. These findings highlight the intricate interplay among intrapersonal, interpersonal, and community factors in shaping adherence behaviors in individuals with schizophrenia.
First, among intrapersonal factors, significant barriers schizophrenia included a lack of insight into and the perceived burden of taking psychiatric medication. Owing to limited understanding of their treatment regimen, negative attitudes, and skepticism toward medication, many patients impulsively discontinued their medication, leading to poor prognosis, disease progression, and relapse. A previous study suggested that individuals with mental illness often believe that their symptoms can improve without medication [
6]. A common reason for discontinuation is the belief that they do not have a mental illness, making them question the necessity of treatment [
18]. Concerns regarding the long-term effects of medication, particularly its impact on life expectancy and cognitive function, further contribute to resistance. Non-adherence to antipsychotic medication is often driven by fear that the medication may be harmful as well as cognitive and attitudinal changes resulting from pharmacological treatment [
6]. These concerns reinforce the reluctance toward adherence. Insufficient information about the medication hindered the participants' understanding of their treatment, which in turn reduced adherence levels [
19]. Therefore, mental health nurses should develop strategies to enhance medication adherence by providing individuals with schizophrenia with accurate and practical information on treatment and medication. Such education can help foster insights into illness, reduce negative perceptions and prejudices about medication, and ultimately improve adherence by addressing individual factors.
The perceived burden of long-term psychiatric medication presented another significant barrier to intrapersonal factors. Many patients experienced discomfort and anxiety in daily life due to side effects, such as weight gain and neuromuscular symptoms. They also feared lifelong dependence on medications, believing that it might be detrimental to their health. Side effects are one of the most common reasons for non-adherence among individuals with mental disorders [
20]. Heightened concerns or negative past experiences related to medication often lead to a substantial decline in adherence [
21]. Therefore, within intrapersonal factors, reducing the perceived burden of psychiatric medication requires a personalized, patient-centered approach. Mental health nurses should assess each patient's unique experiences with side effects and their impact on daily life, providing tailored interventions to enhance self-management strategies and minimize discomfort. Additionally, addressing the patients' fear of longterm medication use during consultations can help alleviate anxiety and improve adherence.
On the other hand, under intrapersonal factors, the acceptance of medication as a form of treatment was a key facilitator of medication adherence. Individuals with mental illness exhibit higher rates of medication adherence when they acknowledge their condition and recognize the value of medication treatment [
22]. Some patients perceived noticeable symptom improvements, including reduced anxiety, increased mental stability, and better impulse control, after initiating psychotropic medication. In a previous study, approximately 11% of patients experienced significant reductions in hallucinations and an overall improvement in functioning due to medication use [
19]. The patients also recognized the importance of medication in preventing relapse. They reported physical discomfort and exacerbated symptoms when skipping doses, which reinforced their commitment to adherence. This aligns with existing research indicating that non-adherence to antipsychotic medication is common among individuals with schizophrenia and is strongly associated with an increased risk of relapse [
5].
Moreover, recognition of the necessity for medication adherence emerged as a crucial factor. Patients acknowledged the importance of continuing medication based on their personal experiences of symptom exacerbation, hospitalization, and overcoming the fear of side effects. Patient motivation is pivotal in promoting adherence, as greater awareness of medication benefits enhances commitment to treatment [
13]. Furthermore, reflecting on positive treatment outcomes, recognizing symptom stabilization, and observing the negative consequences of non-adherence in others have been identified as significant contributors to sustained adherence [
18]. Considering these factors, mental health nurses should play a key role in helping patients gain insight into their illness by experiencing symptom improvement through continued medication use, thereby realizing the necessity for medication adherence and acceptance of treatment.
Second, regarding interpersonal factors, family support and proactive involvement of healthcare providers played a key role in medication adherence among individuals with schizophrenia. Family members were instrumental in ensuring adherence by providing reminders, offering assistance, enhancing the patients' understanding of their treatment regimens, and reducing the risk of non-adherence. These findings are consistent with those of previous studies that have identified family support as a key facilitator of medication adherence [
6,
19,
23]. The presence and active involvement of family members facilitates medication monitoring, supports adherence, and allows for early detection of potential relapse episodes [
18,
23]. To improve medication adherence in individuals with schizo phrenia, it is crucial to educate both patients and their families about psychiatric medications, including their effects, potential side effects, and management. Enhancing family involvement improves patient adherence and treatment outcomes [
23]. In addition, the therapeutic alliance between healthcare providers and patients is essential for improving medication adherence, as it fosters emotional support and provides patients with comprehensive information [
24]. However, negative experiences, such as perceived criticism, insufficient clarity regarding medications and their side effects, and disagreements over treatment approaches, can lead to mistrust between patients and healthcare providers [
24]. This mistrust may result in patients withholding information about their medication use or reducing the frequency of medical visits, ultimately undermining the effectiveness of their treatment regimen [
24]. To enhance medication adherence in patients with schizophrenia, a trust-based relationship with healthcare providers and active family involvement are essential interpersonal factors. To this end, healthcare providers should actively engage with patients, listen to their perspectives, foster open communication, provide clear and comprehensive medication information, and offer emotional support [
18,
24].
Third, regarding community factors, participants perceived that taking psychiatric medication caused feelings of shame, reduced social interaction after disclosing their medication use, and created a sense that their family members disregarded their opinions, ultimately leading to medication avoidance. A previous study identified stigma from family, neighbors, and the community as significant barriers to consistent medication adherence among individuals with psychiatric disorders [
6]. Some individuals avoided taking medication in public because of concerns about revealing their mental illness, which led them to prefer internal medicine clinics over specialized psychiatric services [
25]. Consequently, such stigma not only restricts access to essential mental health resources but also contributes to decreased medication adherence [
25]. Supportive healthcare policies and a more accepting social environment play pivotal roles in enhancing medication adherence and reducing stigma among individuals with schizophrenia [
26]. Media representation also significantly influences societal perceptions of mental health. Media coverage can help reduce the stigma associated with psychiatric disorders [
27]. Individuals with chronic illnesses may struggle with medication self-management owing to stigma-related fear. Therefore, community mental health nurses should adopt a non-judgmental approach and engage in open discussions on medication-related barriers and concerns [
13]. Reducing both social and self-stigma related to psychiatric medication requires an in-depth understanding of patients' perspectives on their mental illness and treatment [
28]. Public awareness campaigns are critical for improving societal attitudes toward psychiatric medications. Positive media portrayals of mental illness play a crucial role in fostering a more informed and accepting society by actively challenging stigma and prejudice [
27]. Thus, in the community, continuous monitoring and critical analysis of media representations of psychiatric medication treatment are necessary to prevent the reinforcement of stigma and misinformation. Furthermore, considering the unique sociocultural context of South Korea, efforts should be made to promote accurate information, foster awareness, and support individuals receiving treatment. Applying an ecological model to understand the interactions at various levels-individual, community, and societal-can offer a comprehensive approach to mitigating stigma and improving treatment adherence.
This study was conducted across three domestic studies, which may limit its ability to fully capture the diverse and multifaceted factors that influence medication adherence among individuals with schizophrenia in different cultural and international healthcare contexts. These factors can vary significantly across sociocultural backgrounds and require careful consideration when applying these findings to diverse settings. There is a pressing need for further research that incorporates an international perspective to understand medication adherence experiences across various cultural backgrounds and healthcare systems. While this study synthesized multiple studies, it is important to acknowledge that some context-specific nuances intrinsic to individual studies may have been overlooked, potentially overlooking subtle yet significant factors that influence medication adherence. Despite these limitations, this study is significant because it provides a comprehensive and integrated exploration of the factors affecting medication adherence in individuals with schizophrenia in South Korea, utilizing a qualitative meta-synthesis methodology. Furthermore, by examining the barriers to and facilitators of medication adherence under intrapersonal, interpersonal, and community factors using an ecological model, this study offers valuable insights into the necessity of multilevel interventions aimed at promoting sustained medication adherence.