Altered single-subject gray matter structural networks in first-episode drug-naïve adolescent major depressive disorder

•This study is the first to perform a graph theory analysis of individual GM morphological networks in a relatively large sample of adolescent MDD patients.•Structural connectome analyses revealed disrupted small-world organization in adolescent MDD patients.•Adolescent MDD patients showed abnormal nodal centralities in the prefronal-subcortical-limbic areas and visual cortex regions.•Altered nodal centralities in the hippocampus were associated with illness duration and symptom severity.