Structural Abnormalities in Depression and Anxiety

Title: Structural Abnormalities Preceding Adolescent Diagnoses of Depression and Anxiety


Type: Master Thesis

Student: Rose Richards

Supervisor: Christian Wachinger

Generalized Anxiety Disorder (GAD) and Major Depressive Disorder (MDD) are two of the most prevalent and frequently co-occurring psychiatric disorders. Many cases of GAD and MDD onset during adolescence (Beesdo et al., 2010; Kessler et al., 2005) and tend to follow a recurrent clinical course that persists into adulthood (Burstein et al., 2014; Rohde et al., 2013). The neural basis of both disorders is still not fully understood, however, and previous results for structural markers of MDD and GAD have been somewhat mixed. Very little is known about early structural markers of MDD and GAD in adolescents, therefore, the present study aims to investigate early structural abnormalities which precede diagnoses among 17 adolescents with GAD, 26 with MDD, 7 with comorbid GAD/MDD, and 1000 healthy controls. We investigate differences in volume, volumetric asymmetry, and shape asymmetry in previously implicated structures—namely, the amygdala, caudate, hippocampus, putamen, and thalamus. Results revealed significant effects of diagnosis on the volume of the putamen and the shape asymmetry of the thalamus. We hypothesize that these early changes that occur in the putamen and thalamus could potentially be a part of the neural correlates of the risk for developing GAD. However, given the small patient sample sizes utilized in the present study, future studies on these structures in adolescents with GAD and MDD are needed to validate this hypothesis.