Anhedonia is a core dimension of major depressive disorder (MDD). Paradoxically, the association between anhedonia and social impairment is poorly known.

To determine the longitudinal relationships between depressive symptoms, anhedonia, and social functioning in depressed patients treated with agomelatine.

One thousand five hundred and seventy patients with MDD starting treatment with agomelatine prescribed by their GPs were included in a prospective study (follow-up: 10 to 14 weeks). Patients were assessed at baseline and at the end point of the study, using the MADRS to assess antidepressant efficacy, the SHAPS scale and an original visual analog scale exploring the subjective pleasure felt by patients in their main leisure activity to measure anhedonia, and the QFS to measure social functioning in its qualitative and quantitative dimensions. In addition to the univariate analyses, a mediation path analysis was performed using the Sobel test.

The results showed a robust and significant improvement in symptoms of depression, anhedonia, and social functioning. The correlations between the SHAPS and QFS scores were high and significant. Subsequent analyses showed that amelioration of anhedonia is a significant mediating variable between the progression of depressive symptoms and social functioning (Δ QFS G = –14.3, P < 0.0001) and explains around one third of the variance of the model (35.37%).

Anhedonia, a major dimension of depression, provides specific insights into the understanding of the complex links between residual symptoms of MDD and social functioning. In conclusion, improving the evaluation of anhedonia is a fundamental issue in primary care.

The authors have not supplied their declaration of competing interest.