Hippocampal volume and parahippocampal cingulum alterations are associated with avoidant attachment in patients with depression

Abstract

• Patients with depression have higher attachment avoidance and anxiety • Depression severity correlates with the extent of avoidant and anxious attachment • High attachment avoidance is linked to smaller hippocampi • High attachment avoidance is linked to parahippocampal cingulum alterations • Results suggest a role of the hippocampal network for avoidant attachment Insecure attachment style (anxious and avoidant) predisposes to the development of depression and has been linked to hippocampal alterations in healthy individuals. However, it is unclear if there are alterations of the hippocampus and the parahippocampal cingulum (PHC) in patients with depression. Forty-eight patients with major depressive disorder and 18 healthy controls underwent MP2RAGE and diffusion-weighted magnetic resonance imaging. Attachment characteristics were assessed with the revised adult attachment scale. Patients were classified into subgroups with low (anxious: n = 27; avoidant: n = 21) and high (anxious: n = 20; avoidant: n = 28) attachment characteristics. Bilateral PHC were reconstructed using manual tractography. Hippocampal volumes, mean fractional anisotropy and mean diffusivity (MD) in bilateral PHC were compared between attachment subgroups and healthy controls. Patients had higher scores of anxious and avoidant attachment, which were associated with depression severity. Patients with high avoidance had decreases in hippocampal volumes in comparison to patients with low avoidance. Furthermore, patients with high avoidance had increased MD in bilateral PHC in comparison to patients with low avoidance and in comparison to healthy controls. Assessment of attachment characteristics may be influenced by cognitive biases due to depressive symptoms High attachment avoidance in patients with depression is associated with volume reductions in the hippocampus and impaired PHC-microstructure.