Preprint
Article

This version is not peer-reviewed.

Moments of Change in Group Psychotherapy: Exploring Therapeutic Factors and Relational Processes

A peer-reviewed version of this preprint was published in:
Behavioral Sciences 2026, 16(8), 1418. https://doi.org/10.3390/bs16081418

Submitted:

12 July 2026

Posted:

14 July 2026

You are already at the latest version

Abstract
Transformative experiences are often described as pivotal mo-ments of change in psychotherapy, yet relatively little is known about how such experiences are perceived within group settings. This study explored how group members and therapists describe transformative in-session moments in group psychotherapy and examined the therapeutic factors and relational processes associated with these ex-periences. Eight semi-structured interviews were conducted with four former group members and four licensed group therapists. Data were analyzed using reflexive thematic analysis, while descriptive counts were used to illustrate the prominence of Yalom’s therapeutic factors in participants’ accounts. All eleven of Yalom’s therapeutic factors were identified in participant narratives, with universality and cohesion emerging most frequently. Moments of change were described as emotionally significant relational experiences characterized by shared humanity, recognition, and meaning-making. Five relational pro-cesses were identified: emotional holding, risk-taking and courage, internalization of the group, therapist emotional presence, and liber-ation from shame. Findings suggest that moments of change emerge through the interplay of relational safety, attuned therapist presence, and courageous interpersonal engagement. The study highlights re-lational processes through which established therapeutic factors be-come experientially meaningful and contribute to psychological change within group psychotherapy and may be associated to psy-chological insight.
Keywords: 
;  ;  ;  ;  ;  ;  ;  ;  

1. Introduction

In every therapeutic encounter, most moments pass unnoticed – and then there are those that change everything. A glance, a shared silence or a timely sentence can initiate profound transformation (Hilzinger et al., 2021). Group psychotherapy is especially rich in such experiences. Within its dynamic relational field change often emerges not through sudden breakthrough but through subtle shifts in how members understand themselves and others (Lewin, 1951; Haas, 2024).
Since its early roots in medical settings (Pinney, 1978), group psychotherapy has been established as an effective treatment across diagnostic presentations (Barkowski et al., 2020; Burlingame et al., 2016). Members enter a “social microcosm” in which interpersonal patterns unfold in the here-and-now (Ends & Page, 1959). Within this relational atmosphere, participants often encounter turning points – emotionally charged interactions that deepen meaning, soften defenses and open new relational possibilities (Yalom & Leszcz, 2020).
Although group therapy research strongly supports its effectiveness, less is known about the lived experience of moments of change as perceived by group members and therapists. Concepts such as Stern et al.’s (1998) “moments of meeting” and insight-based “Aha” experiences (Kounios & Beeman, 2014) highlight relational catalysts, yet empirical studies rarely ask members or therapists to directly identify and describe such experiences (Shen et al., 2015).
Yalom’s eleven therapeutic factors – cohesion, universality, instillation of hope, altruism, interpersonal learning, imitative behavior, catharsis, existential factors, corrective recapitulation of the primary family group, imparting information and development of socializing techniques - remain foundational for understanding mechanisms of change in groups (Behenck et al., 2017; Ponomarenko et al., 2023; Sousa et al., 2020). While cohesion is often viewed as central (Marmarosh et al., 2015; Burlingame, 2018), research shows that the salience of different factors varies depending on group composition and context (Brandão et al., 2019; Wills et al., 2018). This variability underscores that change is dynamic and context-dependent and suggests the value of investigating how factors—and potentially additional processes—manifest in lived therapeutic experience.
Insight has been conceptualized in different ways across psychiatric and psychotherapeutic traditions. In severe psychopathology, particularly psychotic disorders, clinical insight refers to awareness of having a mental disorder, recognition of symptoms, understanding their consequences, and acknowledgment of the need for treatment (David, 1990; Vlachos et al., 2023; Vlachos et al., 2026). In contrast, psychotherapy has traditionally emphasized psychological insight, namely the capacity to achieve meaningful understanding of one’s emotions, relational patterns, internal conflicts, and personal narratives (Jennissen et al., 2018). Although both forms of insight involve increased self-awareness, they differ in focus: clinical insight concerns awareness of illness, whereas psychological insight concerns meaning-making and transformation of subjective experience. Group psychotherapy may constitute a particularly fertile context for the emergence of psychological insight, as individuals come to understand themselves through emotionally significant encounters with others. Moments of change may therefore represent relational contexts in which psychological insight is not simply acquired cognitively, but co-constructed within the interpersonal field of the group.
Importantly, psychological insight should be distinguished from Yalom and Leszcz’s (2020) therapeutic factor of self-understanding. While self-understanding refers to increased awareness of one’s interpersonal patterns, motives, or emotional responses, psychological insight constitutes a broader and more integrative process. It encompasses understanding the associations between past and present experiences, recurring relational patterns, emotional experiences, and psychological difficulties (Jennissen et al., 2018). Beyond cognitive recognition, psychological insight involves emotional meaning-making and transformation in the way individuals experience themselves in relation to others. In this sense, self-understanding may be viewed as one pathway through which psychological insight develops, rather than an equivalent construct.
At a broader level, moments of change are central to Change Process Research (CPR) (Elliott, 2010), which seeks to understand mechanisms of psychotherapeutic change (Burlingame et al., 2016). Drawing on participants’ own accounts positions them as “expert witnesses” of their experience (Elliott, 1984), helping bridge research and clinical practice (Duarte et al., 2019; Gullo et al., 2022). In the present study, moments of change refer to subjectively meaningful in-session experiences retrospectively identified by participants as catalysts of psychological change and transformation, rather than formally coded significant events derived from session-by-session process analysis.
While Yalom and Leszcz’s (2020) therapeutic factors describe broad mechanisms associated with group effectiveness, the experiential enactment of these mechanisms within specific in-session moments remains underexplored. The present study does not seek to introduce additional therapeutic factors. Rather, it explores the phenomenological micro-processes through which established mechanisms become subjectively meaningful and contribute to moments of change within group psychotherapy. In doing so, it contributes to CPR by articulating experiential micro-processes through which broader therapeutic mechanisms become subjectively enacted.
The present study addresses the following research questions:
(1) How do group members and therapists describe in-session moments of change in group psychotherapy?
(2) Which therapeutic factors and relational processes are associated with these moments of change, as reflected in participants’ lived experience?

2. Materials and Methods

2.1. Research Design

A qualitative design using reflexive thematic analysis (Braun & Clarke, 2006, 2021) was employed for its flexibility in capturing emotional and relational processes (Meier et al., 2008). Situated within an experiential qualitative framework, the analysis focused on how participants made meaning of moments of change within group psychotherapy rather than testing predefined constructs (Willig, 2013). In line with reflexive thematic analysis (Braun & Clarke, 2021), knowledge was understood as co-constructed through interaction between participant narratives and researcher interpretation. Rather than attempting to bracket assumptions, the researcher engaged in ongoing reflexive examination of interpretive positions and analytic decisions throughout the process.

2.2. Participants and Eligibility Criteria

Four former group members and four licensed group therapists participated (demographics in Table 1). Members had completed at least one year in ongoing psychotherapy groups but were no longer in treatment, facilitating reflection. Therapists had over three years of experience facilitating groups. This sample was purposive and information-rich. Groups varied in setting (private practice, psychiatric hospital), size (4–8 members) and orientation (group-analytic, psychodynamic, person-centered, Non-Directive Intervention). Interviews with therapists provided context, but analytic focus remained on members’ lived experience. The interview guide is presented in the Appendix A.

2.3. Recruitment and Procedure

Participants were recruited through outreach to group-therapy networks, which disseminated the participant information sheet. Eight individuals expressed interest and met the inclusion criteria; all were interviewed. No individuals who expressed interest declined participation, and no participants were excluded. Written informed consent was obtained prior to interviews.

2.4. Data Collection

Semi-structured interviews invited rich descriptions of transformative group moments. Example prompts included “Can you describe a moment in group therapy that felt transformative?”, “What was happening in the group then?”, and “How did it affect you afterward?”. All of the interview questions are provided in Appendix A. Although interview questions invited participants to describe experiences they perceived as transformative, these experiences are conceptualized in the present study as moments of change within the broader framework of Change Process Research.
Therapists were invited to reflect on Yalom’s therapeutic factors as a reflective prompt during the interview; however, these were not used to structure the analytic coding process. Interviews lasted 20–35 minutes, were recorded, anonymized and transcribed verbatim by the researchers.

2.5. Analysis

Reflexive thematic analysis followed Braun and Clarke’s (2006, 2021) six phases. The dataset generated approximately 300 coded extracts, which informed the development and refinement of the themes. Initial codes were generated inductively through close and repeated engagement with the interview transcripts. Segments of text describing participants’ experiences of moments of change were coded in a flexible and iterative manner, primarily at a semantic level while remaining open to latent relational meanings where these were implied. Coding was recursive; codes were refined, collapsed, or expanded as patterns of shared meaning across participants became visible through ongoing comparison with the dataset. Through this process, related codes were gradually clustered into candidate themes that captured broader patterns in participants’ accounts. These candidate themes were subsequently reviewed against the full dataset and refined to ensure conceptual coherence, internal consistency, and clear distinctions between themes. An illustrative example of the analytic pathway from coded extracts to final themes is presented in the Table 2 to enhance analytic transparency.
During later analytic phases, themes were repeatedly reviewed against the full dataset to ensure coherence, internal consistency, and distinctiveness. Extracts were revisited iteratively to refine thematic boundaries and confirm that themes captured patterned meaning across participants rather than isolated instances.
Thematic development was primarily inductive and data-driven, consistent with reflexive thematic analysis. Yalom’s therapeutic factors were not employed as an a priori coding framework. Rather, once themes had been developed through engagement with participants’ narratives, relevant extracts were subsequently mapped onto Yalom’s conceptual model to explore areas of convergence and divergence between participants’ accounts and established group-change frameworks. This mapping served as a theoretical dialogue with existing frameworks rather than as a deductive analytic structure.
Although not intended for statistical generalization, simple counts were recorded for Yalom’s factors to illustrate descriptive prominence. Counts are presented as heuristic indicators of salience within the dataset rather than as comparative indicators of importance.

2.6. Reflexivity and Analytic Rigor

Reflexivity was an integral part of the research process. The interviews were conducted by the first author, a psychologist with four years of training in group formats and ongoing advanced training in group psychotherapy. This background inevitably shaped interpretive lenses around attunement, cohesion and relational dynamics. Reflexive notes documented assumptions, emotional reactions and interpretive shifts throughout the process (Etherington, 2017). Regular supervision supported methodological integrity (Levitt et al., 2018; Smith, 2021) and helped ensure interpretations remained grounded in participants’ narratives.

2.7. Ethical Considerations

Ethical approval for this study was obtained from the Institutional Review Board of the American College of Greece. All participants provided written informed consent prior to participation. Participation was voluntary, confidentiality was maintained throughout the research process, and identifying information was removed during transcription and reporting.
Given the retrospective and potentially emotionally evocative nature of the interviews, particular attention was paid to participants’ emotional safety. Former group members were informed that participation was entirely voluntary and that they could pause or discontinue the interview at any time without explanation or consequence. Participants were also reminded that they were free to decline answering any question that felt distressing or overwhelming. No participants requested termination of the interview, and no significant distress was observed during data collection.

3. Results

3.1. Presence and Descriptive Frequency of Yalom’s Therapeutic Factors

In line with the qualitative and non-generalizable nature of reflexive thematic analysis, counts are presented to illustrate descriptive prominence and analytic transparency rather than statistical generalization or relative importance. Frequencies for all eleven therapeutic factors appear in Table 3.
All eleven therapeutic factors described by Yalom and Leszcz (2020) were identified in participant narratives, albeit with varying descriptive prominence (see Table 3). Universality and group cohesion were most frequently described, followed by catharsis and existential factors. Imparting information and interpersonal learning appeared with moderate frequency, whereas instillation of hope, altruism, self-understanding, imitative behavior, and corrective recapitulation were less frequently referenced. Overall, moments of change were most often grounded in shared humanity, emotional connection, and meaning.

3.2. Relational Processes Associated with Moments of Change

Five relational processes associated with moments of change were identified across participant accounts, capturing how transformative change was experienced in relational terms (see Table 4). Emotional holding was most frequently described, followed by risk-taking and courage and internalization of the group. Therapist emotional presence and liberation from shame appeared less frequently. Additional representative participant quotations illustrating each theme are provided in Appendix B.

3.2.1. Emotional Holding: “A Place That Could Hold Me”

Emotional holding referred to participants’ experience of feeling emotionally contained, understood, and supported within the group, particularly during moments of vulnerability. Participants described moments of change as occurring when difficult emotions could be shared and carried collectively rather than endured alone.
“It was like the group carried the weight with me… I didn’t feel alone with it for the first time.” (P1)
“They didn’t rush me. They just stayed… That was the moment I realized I could trust them.” (P2)
“Sometimes I felt the whole circle was holding something too heavy for one person to carry alone.” (T1)

3.2.2. Risk-Taking and Courage: “Choosing to Step Forward”

Risk-taking and courage described moments in which participants disclosed previously hidden experiences, expressed difficult emotions, or confronted fears despite uncertainty about how they would be received. Moments of change were frequently associated with these acts of interpersonal courage.
“I can either stay silent or finally say it… and when I said it, everything changed.” (P3)
“My heart was racing… If I say this, everything might change.” (P4)
“Every breakthrough started with someone daring to say what they thought they never would.” (T1)

3.2.3. Internalization of the Group: “Taking the Group Home”

Internalization of the group referred to participants’ experience of carrying the group’s supportive presence beyond the therapy room. Members described drawing upon imagined group responses and internalized relational experiences in their everyday lives.
“Even outside the room, I would think: what would they tell me now?” (P3)
“My secret angel… the part that speaks kindly because they once did.” (P1)
“Patients come back years later and say, ‘The group is still with me in my head.’” (T4)

3.2.4. Therapist Emotional Presence

Therapist emotional presence referred to participants’ experience of the therapist as emotionally attuned, authentic, and genuinely engaged. Moments of change were often linked to the therapist’s way of being rather than specific interventions.
“She looked at me with tears in her eyes… I knew she cared.” (P4)
“It wasn’t what he said. It was how he was with me.” (P2)
“My presence mattered more than my perfect formulation.” (T3)

3.2.5. Liberation from Shame: “From Hiding to Being Seen”

Liberation from shame described experiences in which participants revealed aspects of themselves they expected would be rejected, only to encounter acceptance, recognition, and shared understanding. These moments often marked important shifts in self-perception and interpersonal trust.
“I thought they’d reject me… but they nodded, and I felt human again.” (P1)
“I expected disgust or pity… What I met instead was recognition.” (P4)
“I could almost feel the shame leaving the room when others said, ‘Me too.’” (T1)
Additional participant quotations supporting each theme are presented in Appendix B.

4. Discussion

The findings reaffirm the relevance of Yalom and Leszcz’s (2020) therapeutic factors while showing that their prominence varies across group contexts. At the same time, the analysis identified five emergent processes that deepen our understanding of how transformation unfolds in lived relational experience. These findings suggest that Yalom and Leszcz’s (2020) therapeutic factors may operate at the level of macro-mechanisms of change, whereas the emergent processes identified here illuminate how moments of change are subjectively experienced and enacted within specific in-session interactions.
Although all eleven factors appeared in participants’ narratives, universality and group cohesion were most frequent. This differs from the traditional emphasis on cohesion as the central mechanism (Marmarosh et al., 2005; Burlingame, 2018). In this study, several participants entered therapy with heightened isolation and shame, which may explain why universality—realizing others feel like me—served as the primary gateway to engagement. Similar patterns have been documented in groups facing stigma or identity-related challenges, such as cancer survivors, individuals recovering from alcohol use, and hearing-voices groups (Furnes et al., 2014; Greenfield et al., 2013; Ulman, 2002).
Cohesion remained closely linked to transformation, consistent with research connecting it to emotional safety and therapeutic engagement (Burlingame et al., 2021). Catharsis and existential factors also played notable roles, typically within supportive relational moments. These findings echo evidence that catharsis is most impactful when embedded in cohesive interactions (Groos & Shakespeare-Finch, 2013; Johnson et al., 2006) and align with existential themes observed in previous studies (Vos et al., 2015).
Interpersonal learning and imparting information emerged in participants’ accounts of receiving feedback, recognizing relational patterns, and gaining new perspectives, paralleling research on insight and relational change in group therapy (Joyce et al., 2011; Brouzos et al., 2021). Instillation of hope, altruism, and self-understanding were less frequent but aligned with earlier literature on their supportive roles (Sayin et al., 2008). Imitative behavior and corrective recapitulation appeared rarely, consistent with contemporary findings.
Together, these results support the utility of Yalom’s framework while showing that the experiential core of moments of change was grounded in shared humanity, emotional connection, and meaning making. This context illuminates the five emergent processes identified in this study, which extend the classical model by describing how moments of change were experienced within the group. In doing so, these processes illuminate relational micro-mechanisms of change that are not fully captured by Yalom’s broader therapeutic factors.
An additional interpretation emerging from the present findings is that moments of change may constitute the primary experiential driving force of psychotherapy. Rather than representing isolated significant events, these moments may reflect the experiential culmination or synthesis of multiple therapeutic factors operating simultaneously within the relational field. Experiences of universality, cohesion, altruism, catharsis, interpersonal learning, and emotional holding often converged within a single transformative moment, giving rise to new meanings, emotional shifts, and altered relational expectations. From this perspective, therapeutic factors may be viewed less as separate mechanisms and more as relational conditions that converge in transformative moments. Such moments may therefore represent the lived experiential expression through which therapeutic change becomes psychologically meaningful and enduring.
Building on this perspective, participants’ narratives further suggested the emergence of a broader form of psychological insight. Although self-understanding appeared relatively infrequently as a distinct therapeutic factor, transformative moments often involved not merely recognizing aspects of oneself, but experiencing emotionally significant shifts in self-perception, relational meaning, and personal identity. Psychological insight therefore appeared to extend beyond self-understanding as conceptualized by Yalom and Leszcz (2020), involving the reorganization of emotional, interpersonal and existential meanings within the relational matrix of the group. The present findings further support conceptualizations of insight as a dynamic and evolving process rather than a static capacity (Hazan et al., 2025). Participants’ accounts suggested that psychological insight emerged gradually through repeated relational experiences and emotionally significant encounters within the group. In many accounts, participants described not only understanding something new about themselves, but also experiencing themselves differently in relation to others. Transformative moments may therefore constitute privileged contexts for the emergence of psychological insight within group psychotherapy.

4.1. Emergent Processes

Beyond Yalom’s factors, five relational processes captured additional dimensions of moments of change: emotional holding, risk-taking and courage, therapist emotional presence, internalization of the group, and liberation from shame. Although conceptually overlapping with established factors, participants described these processes as distinct in their lived experience. From a change process perspective, these processes are not proposed as additional therapeutic “factors” in the sense of Yalom’s model. Rather, they represent experiential micro-processes through which change was felt, enacted, and lived within the group context. While therapeutic factors describe broad mechanisms associated with group effectiveness, the present processes illuminate how transformation unfolds moment-to-moment in relational terms, capturing the subjective experience of change rather than its categorical sources.
Although these emergent processes conceptually overlap with established therapeutic factors (e.g., emotional holding with cohesion, liberation from shame with universality, therapist emotional presence with alliance and attunement), they are differentiated here at the level of lived relational quality. The present analysis does not propose categorical distinctions, but phenomenological refinements within broader mechanisms of change.
Taken together, these findings may also be understood through the concept of the therapeutic window (Cole & Barney, 1987). The identified relational processes appeared to create conditions in which emotionally significant experiences could be explored safely and meaningfully. From this perspective, moments of change may represent therapeutic windows within the relational field of the group.
The present findings further suggest that moments of change may represent privileged contexts for the emergence of psychological insight. Whereas clinical insight in severe psychopathology primarily refers to awareness of illness and need for treatment (Vlachos et al., 2023; Vlachos et al., 2026), the moments described by participants reflected a different form of insight: an emotionally grounded understanding of oneself, one’s relational patterns, and one’s place in relation to others. Importantly, such insight did not emerge as an exclusively cognitive achievement or solitary realization. Rather, it appeared to be co-constructed within the relational field of the group through experiences of universality, emotional holding, courageous disclosure, therapist attunement, and liberation from shame. From this perspective, moments of change may constitute the experiential synthesis through which multiple therapeutic factors converge and become psychologically meaningful. In other words, therapeutic factors may create the relational conditions for psychological insight, while moments of change represent the lived experience through which this insight emerges and facilitates transformation.
The present findings invite the hypothesis that moments of change may constitute the primary experiential engine of psychotherapy. Rather than functioning as isolated events, these moments may reflect the culmination of multiple therapeutic processes and the emergence of psychological insight within the relational matrix of the group.

4.1.1. Emotional Holding

Emotional holding resonated strongly with classical and contemporary psychoanalytic perspectives (Winnicott, 1955; Bion, 1962; Slochower, 2011). Participants described the group as a relational container for overwhelming emotional states. This co-constructed holding created a depth of safety that extended beyond cohesion and warranted recognition as a distinct therapeutic process.

4.1.2. Risk-Taking and Courage

Acts of courage—revealing shame-laden material, confronting fear, or speaking difficult truths—were repeatedly described as catalysts for change. Consistent with Shay’s (2021) conceptualization of courage as an emotionally risky decision without guaranteed outcome, these moments frequently preceded catharsis, connection, and enhanced self-understanding.

4.1.3. Internalization of the Group

Internalization emerged as a particularly enduring process. Consistent with object-relations perspectives (Schermer, 2000; Rutan et al., 2014), participants described carrying the group’s voices, emotional stance, and relational imprint into daily life—sometimes years after therapy ended. This ongoing internal resource reflects transformation “beyond the room”, as repeated group experiences become integrated into relational schemas that shape future perceptions of self and others (Baldwin, 1992).
From an attachment-informed perspective, this internalization may reflect the incorporation of corrective relational experiences into evolving internal working models (Mikulincer et al., 2003). The group thus becomes not merely a past experience, but an internalized relational reference point that continues to inform expectations of recognition, safety and mutuality. In line with interpersonal accounts of the relational self (Andersen & Chen, 2002), such relational imprints may be reactivated in new contexts, extending the group’s influence beyond the therapy setting.
Importantly, this process moves beyond the immediate experience of cohesion by highlighting how collective relational experience becomes an enduring psychological resource. In this sense, moments of change in group psychotherapy may contribute not only to in-session change, but to a durable reorganization of relational expectations that persists long after the group has ended.

4.1.4. Therapist Emotional Presence

Participants emphasized the therapist’s authenticity, attunement, and shared affect as central to transformation. This aligns with studies showing that emotional responsiveness enhances alliance and emotional depth (Imel et al., 2014; Furrow et al., 2012; Abargil & Tishby, 2021). Therapists’ reflections echoed research on the importance of self-awareness and emotion regulation during high-affect moments (Putrino et al., 2020). Emotional presence thus emerged as an active mechanism of change.

4.1.5. Liberation from Shame

Shame reduction functioned as another core mechanism. Echoing Shay (2021), participants described fear of humiliation as a major initial barrier; yet group processes—particularly universality and emotional holding—were uniquely capable of dismantling shame. Transformative moments often involved revealing long-hidden aspects of identity or trauma and receiving recognition instead of rejection. This relational disconfirmation of shame reflects shifts seldom achieved in dyadic therapy alone (Davidoff, 2002).

4.2. Influence of Therapeutic Approach

Although therapists represented diverse orientations (group-analytic, psychodynamic, person-centered, and NDI), participants described remarkably similar transformative processes. This supports Bhatt-Mackin and Leszcz’s (2022) observation that core relational mechanisms—attunement, cohesion, and shared meaning—operate across models. While formats varied (e.g., creative techniques), transformative moments were consistently linked to relational rather than model-specific interventions.

4.3. Methodological Considerations

The small, intentionally focused sample supports analytic depth while limiting transferability to structured or short-term groups. In line with qualitative research principles emphasizing information power over sample size (Malterud et al., 2016), the specificity of the research aim, the richness of interview material, and the experiential focus justified a focused sample. Retrospective accounts may privilege emotionally vivid memories over subtle micro-processes. The researcher’s clinical background influenced interpretation; however, reflexive practices were used to enhance transparency and analytic rigor. Additionally, retrospective accounts may reflect processes of meaning-making over time, potentially privileging emotionally salient moments over less vivid but clinically relevant micro-processes.

4.4. Clinical Implications

Findings highlight the importance of cultivating universality, emotional holding and therapist attunement as foundations for transformation. Facilitating acts of courage requires sensitive pacing and an atmosphere of trust. Supporting awareness of internalization may help members sustain change beyond sessions. Overall, relational sensitivity and attention to micro-moments appear central for therapeutic change.

4.5. Future Research Directions

Future work may examine moments of change across different stages of therapy or investigate cultural and identity-based influences on group processes. Micro-analytic studies using session recordings could capture subtle relational dynamics. The emergent processes—especially emotional holding, internalization and shame liberation—may warrant development of process-informed conceptual refinements or qualitative-derived measures.
Future studies may also investigate whether moments of change function as integrative therapeutic events that synthesize multiple therapeutic factors and whether their frequency or quality predicts treatment outcome.
Additionally, another promising direction would be to investigate the relationship between moments of change and the development of psychological insight across the course of psychotherapy. Longitudinal and micro-process research designs may clarify whether transformative moments facilitate enduring increases in self-understanding and whether such increases predict therapeutic outcome. Furthermore, integrating qualitative approaches with existing insight measures may contribute to a more comprehensive understanding of how relational experiences shape both psychological and metacognitive forms of insight.

5. Conclusions

Moments of change in group psychotherapy emerged as emotionally significant relational experiences in which participants felt seen, held and accompanied. The five relational processes identified in this study—emotional holding, risk-taking and courage, therapist emotional presence, internalization of the group and liberation from shame—extend our understanding of how therapeutic change is experienced within groups. Rather than proposing additional therapeutic factors, this study refines our understanding of how established mechanisms become experientially meaningful in participants’ lived experiences. Findings further suggest that transformative moments may represent key relational contexts through which psychological insight emerges and therapeutic change becomes personally meaningful and enduring, enabling participants not only to understand themselves differently, but also to experience themselves differently in relation to others. Even brief moments of connection, recognition, or vulnerability may generate relational shifts that endure beyond the therapy room, carried forward as internalized experiences that continue to shape participants’ relational lives.

Author Contributions

Conceptualization, K.C and I.V.; methodology, K.C. and I.V.; formal analysis, K.C. and I.V.; investigation K.C. and I.V.; data curation, K.C. and I.V.; writing-original draft preparation, K.C.; writing-review and editing, K.C. and I.V.; supervision, I.V. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Institutional Review Board Statement

The study was conducted in accordance with the Declaration of Helsinki and was approved by the Institutional Review Board of the American College of Greece (IRB protocol #202411467, approved on November 2024).

Data Availability Statement

Due to the qualitative nature of the study and the sensitive clinical material involved, the data are not publicly available in order to protect participant confidentiality.

Acknowledgments

The authors would like to extend their heartfelt thanks to Dr. Georgia Georgopoulou and Dr. Nikolaos Pagkalis for their generosity in sharing their clinical experience and professional reflections. We also wish to thank all participants who generously shared their experiences and insights, making this study possible.

Conflicts of Interest

The authors declare no conflicts of interest.

Generative AI Statement

No generative artificial intelligence tools were used in the collection, analysis or interpretation of the data. Generative AI-assisted tools were used only for language editing and formatting support during manuscript preparation.

Appendix A. Interview Guide

For the participants (group members)
  • Can you share a specific moment during group therapy that felt transformative for you? What led to that moment? What happened during that moment?
  • How did you feel before, during, and after the transformative moment? What emotions did it evoke?
  • In what ways did the interactions with other group members contribute to your experience of transformation?
  • How has this transformative experience changed your perspective or behavior outside the therapy? Have you noticed any lasting effects?
  • Were there any challenges or barriers you encountered in the group that might have hindered transformation? How did you overcome them?
For the therapists
  • Can you recall a transformative moment you observed in the group? / What made that moment significant? What was your role in facilitating it?
  • In what ways do you see Yalom’s therapeutic factors playing a role in these transformations? Can you provide examples of how they manifested?
  • How did the group dynamics contribute to the transformation you observed? Were there particular interactions that seemed crucial?
  • How did this transformative experience impact your own understanding of group therapy or your role as a therapist?
  • Have you encountered situations where members struggled to experience transformation? What factors contributed to these challenges?
For participants (group members) and therapists
  • Is there anything else you would like to share about your experience of transformation in group therapy that we haven’t covered?
  • How do you think future group therapy sessions could be improved to facilitate more transformative moments

Appendix B. Participant Quotes by Theme

Emotional Holding: “A Place That Could Hold Me”
“The group hugged my difficulty.”
“I cried and couldn’t say anything. The other member just looked at me with understanding.”
“All the group members hug you and your problem.”
“I felt safe in the group.”
“I didn’t intend to come, but I felt all the warmth and love.”
Risk-Taking and Courage: “Choosing to Step Forward”
“I can either stay silent or finally say it… and when I said it, everything changed.”
“My heart was racing… If I say this, everything might change.”
“He couldn’t say anything and cried in a heartbreaking way.”
“Even though I’m still wearing armor, now it’s not totally closed.”
Internalization of the Group: “Taking the Group Home”
“Even outside the room, I would think: what would they tell me now?”
“My secret angel… the part that speaks kindly because they once did.”
“The members of the group are always with me. I carry them.”
“Even 10 years later I still feel open with the people around me and I want to be close to them.”
Therapist’s Emotional Presence
“She let us see things through our eyes, not hers.”
“It wasn’t what he said. It was how he was with me.”
“Our therapist was amazing… she was the one holding it all together. But always gently.”
“You should be alert to the emotional weather of each member.”
Liberation From Shame: “From Hiding to Being Seen”
“I thought they’d reject me… but they nodded, and I felt human again.”
“I expected disgust or pity… What I met instead was recognition.”
“I was getting a sense of power that I am not the only one.”
“Sometimes you see the other members as a mirror.”

References

  1. Abargil, M.; Tishby, O. How therapists’ emotion recognition relates to therapy process and outcome. Clin. Psychol. Psychother. 2021, 29(3), 1001–1019. [Google Scholar] [CrossRef] [PubMed]
  2. Andersen, S. M.; Chen, S. The relational self: An interpersonal social-cognitive theory. Psychol. Rev. 2002, 109(4), 619–645. [Google Scholar] [CrossRef] [PubMed]
  3. Baldwin, M. W. Relational schemas and the processing of social information. Psychol. Bull. 1992, 112(3), 461–484. [Google Scholar] [CrossRef]
  4. Barkowski, S.; Schwartze, D.; Strauss, B.; Burlingame, G. M.; Rosendahl, J. Efficacy of group psychotherapy for anxiety disorders: A systematic review and meta-analysis. Psychother. Res. 2020, 30(8), 965–982. [Google Scholar] [CrossRef] [PubMed]
  5. Behenck, A.; Wesner, A. C.; Finkler, D.; Heldt, E. Contribution of group therapeutic factors to the outcome of cognitive–behavioral therapy for patients with panic disorder. Arch. Psychiatr. Nurs. 2017, 31(2), 142–146. [Google Scholar] [CrossRef] [PubMed]
  6. Bhatt-Mackin, S.; Leszcz, M. Theories and techniques of group therapy. In Gabbard’s Textbook of Psychotherapeutic Treatments; American Psychiatric Association Publishing, 2022. [Google Scholar] [CrossRef]
  7. Bion, W. R. Learning from experience; Heinemann, 1962. [Google Scholar]
  8. Brandão, T.; Tavares, R.; Schulz, M. S.; Matos, P. M. Experiences of breast cancer patients and helpful aspects of supportive-expressive group therapy: A qualitative study. Eur. J. Cancer Care 2019, 28(5), e13078. [Google Scholar] [CrossRef] [PubMed]
  9. Braun, V.; Clarke, V. Using thematic analysis in psychology. Qual. Res. Psychol. 2006, 3(2), 77–101. [Google Scholar] [CrossRef]
  10. Braun, V.; Clarke, V. Thematic analysis: A practical guide; SAGE Publications, 2021. [Google Scholar]
  11. Brouzos, A.; Vassilopoulos, S. P.; Stavrou, V.; Baourda, V. C.; Tassi, C.; Brouzou, K. O. Therapeutic factors and member satisfaction in an online group intervention during the COVID-19 pandemic. J. Technol. Behav. Sci. 2021, 6(4), 609–619. [Google Scholar] [CrossRef] [PubMed]
  12. Burlingame, G. M.; Strauss, B. Efficacy of small group treatments: Foundation for evidence-based practice. In handbook of psychotherapy and behavior change: 50th anniversary edition, 7th ed.; Barkham, M., Lutz, W., Castonguay, L. G., Bergin, Garfield’s, Eds.; John Wiley & Sons, 2021; pp. 583–624. [Google Scholar]
  13. Burlingame, G. M.; McClendon, D. T.; Yang, C. Cohesion in group therapy: A meta-analysis. Psychother. Theory Res. Pract. 2018, 55(4), 384–398. [Google Scholar] [CrossRef] [PubMed]
  14. Burlingame, G. M.; Strauss, B.; Joyce, A. S. Change mechanisms and effectiveness of small group treatments. In handbook of psychotherapy and behavior change, 6th ed.; Lambert, M. J., Bergin, Garfield’s, Eds.; Wiley, 2016; pp. 640–689. [Google Scholar]
  15. Cole, C. H.; Barney, E. E. Safeguards and the therapeutic window: A group treatment strategy for adult incest survivors. Am. J. Orthopsychiatry 1987, 57(4), 601–609. [Google Scholar] [CrossRef] [PubMed]
  16. David, A. S. Insight and psychosis. Br. J. Psychiatry J. Ment. Sci. 1990, 156, 798–808. [Google Scholar] [CrossRef] [PubMed]
  17. Davidoff, F. Shame: The elephant in the room. BMJ 2002, 324(7338), 623–624. [Google Scholar] [CrossRef] [PubMed]
  18. Duarte, S.; Martinez, G.; Tomicic, S. Relevant episodes and events for the study of change in psychotherapy. Rev. Argent. De Clínica Psicológica 2019, 28(3), 253–265. [Google Scholar] [CrossRef]
  19. Elliott, R. A discovery-oriented approach to significant change events in psychotherapy: Interpersonal process recall and comprehensive process analysis. In Patterns of change: Intensive analysis of psychotherapy process; Rice, L., Greenberg, L. S., Eds.; Guilford Press, 1984; pp. 249–286. [Google Scholar]
  20. Elliott, R. Psychotherapy change process research: Realizing the promise. Psychother. Res. 2010, 20(2), 123–135. [Google Scholar] [CrossRef] [PubMed]
  21. Ends, E. J.; Page, C. W. Group psychotherapy and concomitant psychological change. Psychol. Monogr. General. Appl. 1959, 73(10), 1–31. [Google Scholar] [CrossRef]
  22. Etherington, K. Personal experience and critical reflexivity in counselling and psychotherapy research. Couns. Psychother. Res. 17 (2) 2017, 85–94. [Google Scholar] [CrossRef]
  23. Furnes, B.; Natvig, G. K.; Dysvik, E. Therapeutic elements in a self-management approach: Experiences from group participation among people suffering from chronic pain. Patient Prefer. Adherence 2014, 8, 1085–1092. [Google Scholar] [CrossRef] [PubMed]
  24. Furrow, J. L.; Edwards, S. A.; Choi, Y.; Bradley, B. Therapist presence in emotionally focused couple therapy blamer softening events: Promoting change through emotional experience. J. Marital Fam. Ther. 2012, 38 (suppl. 1), 39–49. [Google Scholar] [CrossRef] [PubMed]
  25. Greenfield, S. F.; Kuper, L. E.; Cummings, A. M.; Robbins, M. S.; Gallop, R. Group process in the single-gender women’s recovery group compared with mixed-gender group drug counseling. J. Groups Addctn. Recovery 2013, 8(4), 270–293. [Google Scholar] [CrossRef] [PubMed]
  26. Groos, A.; Shakespeare-Finch, J. Positive experiences for participants in suicide bereavement groups: A grounded theory model. Death Stud. 2013, 37(1), 1–24. [Google Scholar] [CrossRef] [PubMed]
  27. Gullo, S.; Coco, G. L.; Leszcz, M.; Marmarosh, C. L.; Miles, J. R.; Shechtman, Z.; Tasca, G. A. Therapists’ perceptions of online group therapeutic relationships during the COVID-19 pandemic: A survey-based study. Group Dyn. Theory Res. Pract. 2022, 26(2), 103–118. [Google Scholar] [CrossRef]
  28. Haas, W. Group therapy and group dynamic theory, 1st ed.; Taylor & Francis, 2024. [Google Scholar]
  29. Hazan, H.; Ferrara, M.; Gibbs-Dean, T.; Tayfur, S. N.; Corbera, S.; Karmani, S.; Song, Z.; Li, F.; Vlachos, I.; Selakovic, M.; Tek, C.; Srihari, V. H. Insight and Its Trajectory: Predicting the Risk of Psychiatric Hospitalizations Among First-Episode Psychosis During the First Year of Coordinated Specialty Care. Schizophr. Bull. 2026, 52(1), sbaf019. [Google Scholar] [CrossRef] [PubMed]
  30. Hilzinger, R.; Duarte, J.; Hench, B.; Hunger, C.; Schweitzer, J.; Krause, M.; Fischersworring, M. Recognizing oneself in the encounter with others: Meaningful moments in systemic therapy for social anxiety disorder in the eyes of patients and their therapists after the end of therapy. PLoS ONE 2021, 16(5), e0250094. [Google Scholar] [CrossRef] [PubMed]
  31. Imel, Z. E.; Barco, J. S.; Brown, H. J.; Baucom, B.; Baer, J. S.; Kircher, J. C.; Atkins, D. C. The association of therapist empathy and synchrony in vocally encoded arousal. J. Couns. Psychol. 2014, 61(1), 146–153. [Google Scholar] [CrossRef] [PubMed]
  32. Jennissen, S.; Huber, J.; Ehrenthal, J. C.; Schauenburg, H.; Dinger, U. Association Between Insight and Outcome of Psychotherapy: Systematic Review and Meta-Analysis. Am. J. Psychiatry 2018, 175(10), 961–969. [Google Scholar] [CrossRef] [PubMed]
  33. Johnson, J. E.; Pulsipher, D. T.; Ferrin, S. L.; Burlingame, G. M.; Davies, D. R.; Gleave, R. Measuring group processes: A comparison of the GCQ and CCI. Group Dyn. Theory Res. Pract. 2006, 10(2), 136–145. [Google Scholar] [CrossRef]
  34. Joyce, A. S.; MacNair-Semands, R.; Tasca, G. A.; Ogrodniczuk, J. S. Factor structure and validity of the Therapeutic Factors Inventory–Short Form. Group Dyn. Theory Res. Pract. 2011, 15(3), 201–219. [Google Scholar] [CrossRef]
  35. Kounios, J.; Beeman, M. The cognitive neuroscience of insight. Annu. Rev. Psychol. 2014, 65(1), 71–93. [Google Scholar] [CrossRef] [PubMed]
  36. Levitt, H. M.; Bamberg, M.; Creswell, J. W.; Frost, D. M.; Josselson, R.; Suárez-Orozco, C. Journal article reporting standards for qualitative primary, qualitative meta-analytic, and mixed methods research in psychology: The APA Publications and Communications Board task force report. Am. Psychol. 2018, 73(1), 26–46. [Google Scholar] [CrossRef] [PubMed]
  37. Lewin, K. Field theory in social science; American Psychological Association, 1951. [Google Scholar]
  38. Malterud, K.; Siersma, V. D.; Guassora, A. D. Sample size in qualitative interview studies: guided by information power. Qual. Health Res. 2016, 26(13), 1753–1760. [Google Scholar] [CrossRef] [PubMed]
  39. Marmarosh, C.; Holtz, A.; Schottenbauer, M. Group cohesiveness, group-derived collective self-esteem, group-derived hope, and the well-being of group therapy members. Group Dyn. Theory Res. Pract. 2005, 9(1), 32–44. [Google Scholar] [CrossRef]
  40. Meier, A.; Boivin, M.; Meier, M. Theme-analysis: Procedures and application for psychotherapy research. Qual. Res. Psychol. 2008, 5(4), 289–310. [Google Scholar] [CrossRef]
  41. Mikulincer, M.; Shaver, P. R.; Pereg, D. Attachment theory and affect regulation: The dynamics, development, and cognitive consequences of attachment-related strategies. Motiv. Emot. 2003, 27(2), 77–102. [Google Scholar] [CrossRef]
  42. Pinney, E. L. Paul Schilder and group psychotherapy: The development of psychoanalytic group psychotherapy. Psychiatr. Q. 1978, 50(2), 133–143. [Google Scholar] [CrossRef] [PubMed]
  43. Ponomarenko, P.; Seragnoli, F.; Calder, A. E.; Oehen, P.; Hasler, G. Can psychedelics enhance group psychotherapy? A discussion on the therapeutic factors. J. Psychopharmacol. 2023, 37(7), 660–678. [Google Scholar] [CrossRef] [PubMed]
  44. Putrino, N.; Casari, L. M.; Mesurado, B.; Etchevers, M. Psychotherapists’ emotional and physiological reactions toward patients with either borderline personality disorder or depression. Psychother. Res. 2020, 30(7), 912–919. [Google Scholar] [CrossRef] [PubMed]
  45. Rutan, J. S.; Stone, W. N.; Shay, J. J. Psychodynamic group psychotherapy, 5th ed.; Guilford Press, 2014. [Google Scholar]
  46. Sayin, A.; Karslioğlu, E. H.; Sürgit, A.; Sahin, S.; Arslan, T.; Candansayar, S. Perceptions of Turkish psychiatric inpatients about therapeutic factors of group psychotherapy. Int. J. Group Psychother. 2008, 58(2), 253–263. [Google Scholar] [CrossRef] [PubMed]
  47. Schermer, V. L. Contributions of object relations theory and self psychology to relational psychology and group psychotherapy. Int. J. Group Psychother. 2000, 50(2), 199–217. [Google Scholar] [CrossRef] [PubMed]
  48. Shay, J. J. Terrified of group therapy: Investigating obstacles to entering or leading groups. Am. J. Psychother. 2021, 74(2), 71–75. [Google Scholar] [CrossRef] [PubMed]
  49. Shen, W.; Yuan, Y.; Chang, L.; Luo, J. In search of the ‘aha!’ experience: Elucidating the emotionality of insight problem-solving. Br. J. Psychol. 2015, 107(2), 281–298. [Google Scholar] [CrossRef] [PubMed]
  50. Slochower, J. Holding and listening. Psychoanal. Dialogues 2011, 21(5), 498–512. [Google Scholar]
  51. Smith, J. A.; Larkin, M.; Flowers, P. Interpretative phenomenological analysis: Theory, method and research; SAGE Publications, 2021. [Google Scholar]
  52. Sousa, J. M.; Vale, R. R. M. D.; Pinho, E. S.; Almeida, D. R.; Nunes, F. C.; Farinha, M. G.; Esperidião, E. Effectiveness of therapeutic groups in psychosocial care: Analysis in the light of Yalom’s therapeutic factors. Rev. Bras. De Enferm. 2020, 73 (Suppl. 1), e20200410. [Google Scholar] [CrossRef] [PubMed]
  53. Stern, D. N.; Bruschweiler-Stern, N.; Harrison, A. M.; Lyons-Ruth, K.; Morgan, A. C.; Nahum, J. P.; Sander, L.; Tronick, E. Z. The process of therapeutic change involving implicit knowledge: Some implications of developmental observations for adult psychotherapy. Infant Ment. Health J. 19 1998, 300–308. [Google Scholar] [CrossRef]
  54. Ulman, K. H. The ghost in the group room: Countertransferential pressures associated with conjoint individual and group psychotherapy. Int. J. Group Psychother. 2002, 52(3), 387–407. [Google Scholar] [CrossRef] [PubMed]
  55. Vlachos, I. I.; Selakovic, M.; Ralli, I.; Hatzimanolis, A.; Xenaki, L.-A.; Dimitrakopoulos, S.; Soldatos, R.-F.; Foteli, S.; Nianiakas, N.; Kosteletos, I.; Stefanatou, P.; Ntigrintaki, A.-A.; Triantafyllou, T.-F.; Voulgaraki, M.; Ermiliou, V.; Mantonakis, L.; Kollias, K.; Stefanis, N. C. Role of Clinical Insight at First Month in Predicting Relapse at the Year in First Episode of Psychosis (FEP) Patients. J. Clin. Med. 2023, 12(13), 4261. [Google Scholar] [CrossRef] [PubMed]
  56. Vlachos, I. I. Early clinical insight in first-episode psychosis. Schizophr. Res. Cogn. 2026, 45, 100447. [Google Scholar] [CrossRef] [PubMed]
  57. Vos, J.; Craig, M.; Cooper, M. Existential therapies: A meta-analysis of their effects on psychological outcomes. J. Consult. Clin. Psychol. 2015, 83(1), 115–128. [Google Scholar] [CrossRef] [PubMed]
  58. Willig, C. Introducing qualitative research in psychology (eBook); McGraw-Hill Education, 2013. [Google Scholar]
  59. Wills, S.; Robbins, L.; Ward, T.; Christopher, G. Significant therapy events with clients with intellectual disabilities. Adv. Ment. Health Intellect. Disabil. 2018, 12(5/6), 173–183. [Google Scholar] [CrossRef]
  60. Winnicott, D. W. The maturational processes and the facilitating environment. Int. J. Psycho-Anal. 36 1955, 1–9. [Google Scholar]
  61. Yalom, I. D.; Leszcz, M. The theory and practice of group psychotherapy, 6th ed.; Basic Books, 2020. [Google Scholar]
Table 1. Participants’ characteristics and group context.
Table 1. Participants’ characteristics and group context.
Participant Role Age Range Gender Group Setting Group Orientation Duration in Group Session Length
P1 Member 50-59 Female Private Practice Group-Analytic >3 year 2h
P2 Member 50-59 Male Private Practice Person-Centered >1 year 1.5-2h
P3 Member 30-39 Female Private Practice Psychodynamic >2 years 1.5-2h
P4 Member 60-69 Male Private Practice Non-Directive Intervention (NDI) >2 years 2h
T1 Therapist 50-59 Male Private Practice Group-Analytic >5 years experience 2h
T2 Therapist 50-59 Male Private Practice Group-Analytic >8 years experience 2h
T3 Therapist 50-59 Female Private Practice Person-Centered >10 years experience 1.5-2h
T4 Therapist 40-49 Female Psychiatric Hospital Group-Analytic >2 years experience 2h
Note. Members refer to former group therapy participants; therapists refer to licensed group psychotherapists facilitating groups at the time of the study.
Table 2. Illustrative pathway from coded extracts to final themes.
Table 2. Illustrative pathway from coded extracts to final themes.
Initial Code Illustrative Extract Interpretive Pattern Final Theme
Feeling supported by the group during emotional disclosure “It was like the group carried the weight with me… I didn’t feel alone with it.” Shared emotional containment within the group Emotional holding
Group members remaining present during intense emotion “They didn’t rush me. They just stayed.” Relational safety created through collective presence Emotional holding
Fear before revealing something personal “My heart was racing… If I say this, everything might change.” Transformation following interpersonal risk Risk-taking and courage
Speaking openly despite fear of judgment “I can either stay silent or finally say it… and when I said it, everything changed.” Courageous interpersonal engagement Risk-taking and courage
Imagining the group’s voice outside sessions “Even outside the room I would think: what would they tell me now?” Internalized relational presence of the group Internalization of the group
Carrying the group’s emotional stance into everyday life “The members of the group are always with me. I carry them.” Internalized relational resource Internalization of the group
Therapist emotional attunement “She looked at me in a way that I knew she cared about me.” Affective attunement Therapist emotional presence
Therapist relational presence during vulnerable moments “It wasn’t what he said. It was how he was with me.” Experiencing the therapist as emotionally present Therapist emotional presence
Disclosure of shame followed by acceptance “I thought they’d reject me… but they nodded.” Relational disconfirmation of shame Liberation from shame
Recognition from others after shameful disclosure “I expected disgust or pity… what I met instead was recognition.” Transformation through shared humanity Liberation from shame
Note The table provides illustrative examples of how coded extracts informed the development of interpretive patterns and final themes. It is intended to demonstrate the analytic pathway rather than to represent the full coding structure.
Table 3. Descriptive frequencies of Yalom’s therapeutic factors across participant interviews.
Table 3. Descriptive frequencies of Yalom’s therapeutic factors across participant interviews.
Therapeutic Factor Frequency (n)
Universality 11
Group cohesion 9
Catharsis 7
Existential Factors 7
Imparting information 6
Interpersonal learning 6
Instillation of hope 5
Altruism 4
Self-understanding 4
Imitative behavior 2
Corrective recapitulation 2
Note. Counts are provided only as heuristic indicators of descriptive prominence within the dataset and are not intended to imply quantitative comparison or statistical significance.
Table 4. Relational Processes Associated with Moments of Change.
Table 4. Relational Processes Associated with Moments of Change.
Emotional holding 7
Risk-taking and courage 5
Internalization of the group 5
Therapist’s emotional presence 4
Liberation from shame 3
Note. Processes are presented in order of descriptive prominence within the dataset.
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.
Copyright: This open access article is published under a Creative Commons CC BY 4.0 license, which permit the free download, distribution, and reuse, provided that the author and preprint are cited in any reuse.