Surface-based analysis of early cortical gyrification and thickness alterations in treatment-Naïve, first-episode depressive patients during emerging adulthood.

Background: Extensive research, predominantly in adults, has highlighted structural brain variations among patients with major depressive disorder (MDD). However, emerging adults, who undergo significant cortical reshaping and are highly vulnerable to depression, receive relatively little attention, despite reporting a higher prevalence of childhood trauma experiences. This study examines cortical gyrification and thickness in emerging adults with first-episode, treatment-naïve MDD, with the objective of investigating their association with childhood trauma.

Methods: Eighty-six emerging adults diagnosed with MDD, aged 18 to 25, and eighty-one healthy controls (HCs), underwent T1-MRI scans. We compared the local gyrification index (LGI) and cortical thickness (CT) between the two groups. Subsequently, we examined the relationship between the LGI and CT in clusters showing differences and childhood trauma as well as clinical characteristics in emerging adults with MDD.

Results: Compared to HCs, MDD showed decreased LGI in the bilateral superior frontal cortices (SFC) and CT in the left pericalcarine cortex (PCC), while an increase in CT was observed in the left lateral orbitofrontal cortex (OFC). The reduction in LGI of the right SFC and the decrease in CT of the left PCC are associated with childhood trauma. Notably these brain abnormalities were not significantly associated with depressive and anxiety symptoms, or the duration of illness.

Conclusion: Abnormal cortical development observed in emerging adults with first episode depression may act as a predisposing factor for depression, irrespective of clinical manifestations, and may be linked to childhood trauma.