Adult attachment insecurity and hippocampal cell density

Abstract

Recent findings associate attachment insecurity (assessed as levels of attachment anxiety and avoidance) with poor emotion regulation. In turn, emotion regulation has been shown to be associated with hippocampus (HC) functioning and structure. Clinical disorders such as depression and PTSD, which have been previously associated with attachment insecurity, are also known to be linked with reduced hippocampal cell density. This suggests that attachment insecurity may also be associated with reduced hippocampal cell density. We examined this hypothesis using T1 images of 22 healthy young adults. In line with our hypothesis, attachment avoidance was associated with bilateral HC reduction, whereas attachment anxiety was significantly related to reduced cell concentration in the left HC. The findings are compatible with a neurotoxical model of stress-induced cell reduction in the HC, providing further information on emotion regulation abilities among insecurely attached individuals.

Figures

Fig. 1

Scatter plot for the correlation between attachment anxiety and gray matter concentration in the left hippocampus corrected for the influence of gender. r = −0.72, P < 0.001; r = −0.69, P < 0.001, after elimination of an outlier greater than M ± 3 SD.

Fig. 2

Scatter plot for the correlation between attachment avoidance and gray matter concentration in the left hippocampus corrected for the influence of gender. r = −0.63, P < 0.01; r = −0.49, P < 0.05, after elimination of an outlier greater than M ± 3 SD.

Fig. 3

Scatter plot for the correlation between attachment avoidance and gray matter concentration in the right hippocampus corrected for the influence of gender. r = −0.63, P < 0.01; r = −0.48, P < 0.05, after elimination of an outlier greater than M ± 3 SD.

Fig. 4

Clusters of gray matter concentration in the hippocampus correlated with attachment styles. Lower gray matter concentrations in the left hippocampus were found for participants with high attachment anxiety scores (left). Lower gray matter concentration in the left as well as in the right hippocampus were found for participants with higher attachment avoidance scores (right). Statistical cluster maps are overlaid on the average brain of the sample; t-maps show differences in gray matter concentration at each gray matter voxel of the brain; all clusters (defining threshold of P < 0.001) are shown in the sagittal, coronal and horizonal view.