Authors:
Dr. Marie-Laure Paillère Martinot | APHP, CHU Cochin | France
Dr. Hélène Vulser | APHP, Hôpital Européen Georges Pompidou
Dr. Nadège Bourvis | APHP, CHU Pitié Salpêtrière | French Polynesia
Dr. Eric Artiges | INSERM
Dr. Jean-Pierre Benoît | APHP, CHU Cochin
Dr. Marie Douniol | Erasme hospital | France
PhD Nora Bouaziz | Erasme hospital
Prof. David Cohen | APHP, CHU Pitié Salpêtrière
Prof. Richard Delorme | APHP, Robert Debré hospital
Dr. Coline Stordeur | APHP, Robert Debré hospital
Ruben Miranda | INSERM
Irina Filippi | INSERM
Dr. Jean-Luc Martinot | INSERM
PhD Herve Lemaitre | University Paris-Sud 11 | France
The IMAGEN Consortium
Objectives: Adolescence is a period of transition related to structural brain circuit remodelling, involving myelination as one mechanism. The adolescent affective phenomenology might include major depression episodes or subthreshold pictures, subthreshold depression in adolescence being a risk factor for Major Depressive Disorder in late adolescence or adulthood. We aimed to identify the changes in brain morphometry and white matter microstructure in emotion regions associated with affective symptoms in adolescents, and their relation to depression outcomes.
Methods: In a first study, the participants were extracted from the European Imagen database of community 14-year-old adolescents followed up at age 16. Ninety-six adolescents with subthreshold depression were compared to matched controls. In a second study, 21 adolescents with a Major Depressive Episode diagnosis were compared to matched controls and followed up a year later. All participants were investigated using using 3T T1-Magnetic Resonance Imaging and Diffusion Tensor imaging (DTI). All had completed a diagnostic computerized interview that allows for symptom assessment. Voxel-wise comparisons were performed using statistical parametric mapping (SPM8) for structural MRI, and using tract-based spatial statistics (TBSS) for DTI parameters.
Results: In adolescents with subthreshold depression, grey matter volumes of the medial prefrontal cortex and caudates were smaller than in controls, and lower fractional anisotropy (FA) was found in several white matter tracts, mainly the genu of the corpus callosum and the cingulum. In adolescents with major depression, smaller grey matter volumes were observed in the hippocampus and precuneus regions, and FA decreases were observed in the genu of the corpus callosum and in the uncinate fasciculus. In adolescents with subthreshold depression, smaller medial-prefrontal grey matter volume and lower FA in the corpus callosum at age 14 partly predicted depression outcome at age 16.
Conclusion: Adolescents with subthreshold or full depression exhibited impaired structural connectivity that might indicate altered white matter tract maturation and contribute to the transition to affective disorders.