Depression in Adolescents. A Cerebral Structural, Diffusion, and Functional Magnetic Resonance Imaging Study

Adolescence is a critical period for the development of depressive disorders. As adolescence also is a critical period for brain maturation, it may be hypothesized that maturation changes in emotional circuits could underlie vulnerability for depression. The aims of the study are (1) to identify the changes in brain morphometry, white matter microstructure, and functioning, in networks associated with depression features in adolescents, and (2) to assess the effects of treated pathology on brain structure by comparing the neuroimaging measures obtained in adolescents at inclusion with those at follow-up.

Adolescence is a key development period for neurobiological processes underlying emotional and cognitive functions in adulthood. The pathophysiology of mood disorders has recently been associated with maturation changes in brain networks, but little is known on the early brain structure changes associated with depression appearing during this major brain maturation period. The hypothesis of altered structural integrity of limbic prefrontal pathways emerges from the literature on depression, but it is unknown whether it is also detectable in adolescents with depression. Thus, we aim to investigate WM and GM structure and anatomy, and functional correlates of behavioral responses in depressed adolescents. 40 adolescents with a Major Depressive Episode will be investigated using structural T1 magnetic-resonance imaging and diffusion tensor imaging (DTI), at inclusion and after one-year follow-up. Additionally, they will be investigated with fMRI. Covariation patterns between neuroimaging and behavioural/clinical variables will be assessed.