## 6 Discussion: The Critical Role of Twin Studies in Examining the Association Between CDS and ED
This would be particularly important from a clinical perspective, given that only a limited number of studies have explored the effectiveness of interventions in reducingsymptons related to CDS and its associated impairments [4; 77]. To date, no intervention has been specifically designed for individuals with CDS [4]. Considering the established association between CDS and ED [2; 69; 70; 71], treatment protocols for psychiatric disorders involving individuals with high levels of CDS symptoms could benefit from incorporating techniques aimed at enhancing emotional awareness and regulation, such as Dialectical Behavior Therapy (DBT) [78] techniques. Moreover, the few available twin studies suggest that while both CDS and ED have strong genetic underpinnings, they are primarily influenced by non-shared environmental factors [12; 39; 42; 44; 45]. Therefore, it is plausible that psychosocial factors (e.g., peer rejection, adverse school experiences) play a significant role as risk factors for psychological distress and could represent key targets for clinical intervention. Future research should focus on clarifying the causal mechanisms underlying the relationship between CDS and Emotional Dysregulation (ED), particularly in developmental terms. [PERSON] et al. [4] highlighted the presence of Emotional Dysregulation profiles in youth with CDS, suggesting it may represent a core clinical feature of the syndrome. However, as ED is also frequently observed in individuals with ADHD, future studies should account for the potential confounding effects of CDS-ADHD comorbidity to determine the specificity of this association. Given the current conceptual ambiguity and the early stage of the literature, further efforts are needed to standardize definitions and measurements to enhance reliability across twin and genetically informed studies. In addition, it will be crucial to explore how early interventions may influence developmental trajectories, especially when considering the role of non-shared environmental factors in shaping treatment outcomes. Advancing this line of research will not only refine our understanding of CDS but also support the development of targeted clinical strategies grounded in more precise etiological models. Conceptualization, G.D.G., C.A., S.D.F., L.G. and S.S.; investigation, G.D.G. and C.A. ; writing--original draft preparation, G.D.G., C.A., G.T. and F.G.; writing--review and editing, G.D.G., C.A., S.D.F., L.G., M.C., B.F. and S.S.; supervision, S.D.F., L.G., M.C., B.F. and S.S.; project administration, S.S. All authors have read and agreed to the published version of the manuscript. This research received no external funding. The contributions presented in this study are included in the cited articles; further inquiries can be directed to the corresponding author. The authors declare no conflicts of interest. The following abbreviations are used in this manuscript: \begin{tabular}{l l} ADHD & Attention-Deficit/Hyperactivity Disorder \\ CDS & Cognitive Disengagement Syndrome \\ ED & Emotional Dysregulation \\ rGE & Genotype-Environment correlation \\ A & Additive genetic effects \\ C & Shared environmental effects \\ E & Unique environmental effects \\ MZ & Monozygotic \\ DZ & Dizygotic \\ \end{tabular}