Pathways to anhedonia in unmedicated major depressive disorder: the roles of insecure attachment and emotion dysregulation.

Background: Anhedonia, emotion regulation difficulties, and insecure attachment are clinically relevant features of major depressive disorder (MDD); however, their interrelationships have rarely been examined within a single model in unmedicated clinical samples. We tested whether insecure attachment is associated with depression severity through limited access to emotion regulation strategies and anhedonia. Methods: The sample comprised 102 medication-free patients with MDD (≥6 months without psychotropic medication) and 102 controls selected using predefined matching criteria. Diagnoses were established using the Structured Clinical Interview for DSM-5 Disorders-Clinician Version. Depression severity and anhedonia were assessed using the clinician-administered Hamilton Depression Rating Scale and Snaith-Hamilton Pleasure Scale-Clinician-Administered Version, respectively; attachment and emotion regulation difficulties were assessed using the self-report Relationship Scales Questionnaire and Difficulties in Emotion Regulation Scale. Group comparisons, multivariable logistic regression, and a path model within the MDD group were conducted, with indirect effects tested using bias-corrected bootstrap resampling. Results: Patients with MDD showed lower secure attachment, higher fearful and preoccupied/anxious attachment, greater overall emotion regulation difficulties, and higher anhedonia than controls. In multivariable logistic regression, DERS-Strategies (OR = 1.21, 95% CI = 1.07-1.38) and SHAPS-C (OR = 1.54, 95% CI = 1.20-1.99) were independently associated with MDD status (Nagelkerke R² = 0.77). In the path model, fearful (β = 0.377) and preoccupied/anxious (β = 0.220) attachment were associated with DERS-Strategies, which in turn was associated with both SHAPS-C (β = 0.431) and HAM-D (β = 0.271); SHAPS-C was independently associated with HAM-D (β = 0.238). The sequential indirect path from fearful attachment to HAM-D through DERS-Strategies and SHAPS-C was significant (β = 0.163, 95% bootstrap CI = 0.050-0.411, p = 0.007). In exploratory analyses, SHAPS-C was positively associated with MDD status but inversely associated with recurrent episode status (OR = 0.68, 95% CI = 0.53-0.88). Conclusion: In an unmedicated MDD sample, insecure attachment, limited access to emotion regulation strategies, anhedonia, and depression severity were linked in a coherent sequential association pattern, with DERS-Strategies occupying a central position. The differential association of anhedonia across MDD status and recurrent episode presentation is exploratory and warrants confirmation in longitudinal studies.