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.