Facteurs de risque de développement de troubles intériorisés : études en Imagerie par Résonance Magnétique structurelle
Several risk factors for the development of internalized disorders such as anxiety, depression, and bipolar disorders have been identified in the literature. The two most important risk factors include adversity during childhood (i.e. abuse, neglect and harsh parenting) and parental risk (i.e. the presence of an internalized disorder in one or both parents). These risk factors have been linked to anatomical changes in several brain structures, which are similar to those observed in internalized disorders. Thus, in the presence of these risk factors, anatomical abnormalities may predict the appearance of internalized disorders in asymptomatic individuals. In the few studies that have investigated the influence of these risk factors in a youth population, participants often had comorbidities and/or were medicated, which makes the observed anatomical changes difficult to interpret. This work has focused on these two risk factors (i.e. adversity during childhood, in the form of harsh parenting, and the parental risk) and their link with the anatomical cerebral substrates, in asymptomatic and un-medicated adolescents. A first study examined the link between harsh parenting, levels of anxiety symptoms, as measured longitudinally from birth, and neuroanatomical differences in adolescents (see Chapter 2). A second study examined the link between parental risk of developing anxiety disorders, and neuroanatomical differences in adolescents (see Chapter 3). A third study looked at the link between parental risk for developing depressive disorder or bipolar disorder, and neuroanatomical differences in adolescents (see Chapter 4). Results show differences in volume and/or cortical thickness of several key cerebral structures involved in emotional processing and regulation. This is the case of the prefrontal cortex, orbitofrontal cortex, anterior cingulate cortex, the amygdala, hippocampus and striatum. These results suggest that some neuroanatomical differences in internalized disorders may be present before the disorder emerges, and represent neuronal markers denoting the risk of developing the disorder. The theoretical implications and limitations of these three studies are discussed in Chapter 5.
FreeSurfer Adversity Parental risk internalized disorder Anxiety FreeSurfer MRI