Hippocampal volume changes in healthy subjects at risk of unipolar depression

Abstract

a b s t r a c tUnipolar depression is moderately heritable. It is unclear whether structural brain changes associated with unipolar depression are present in healthy persons at risk of the disorder. Here we investigated whether a genetic predisposition to unipolar depression is associated with structural brain changes. A priori, hippocampal volume reductions were hypothesized. Using a high-risk study design, magnetic resonance imaging brain scans were obtained from 59 healthy high-risk subjects having a co-twin with unipolar depression, and 53 healthy low-risk subjects without a first-degree family history of major psychiatric disorder. High-risk twins had smaller hippocampal volumes than low-risk twins (p < 0.04). The finding was most pronounced in DZ twins. Groups did not differ on global brain tissue volumes or regional tissue volumes assessed in exploratory voxel-wise whole cerebrum analyses. In conclusion, hippocampal volume reduction may index a predisposition to develop depression and thus may be predictive of future onset of the disorder. Further studies are needed to elucidate the role of (shared) environmental and genetic factors.

The Effects of Psychotherapy on Brain Function — Major Depressive Disorder

“…After processing the comparison, the volume of the hippocampus and prefrontal cortex was significantly reduced in the group with a family history of depression. [13,14] This result explains some of the hereditary aspects of depression, thereby indicating the association of the neuroimaging findings with the risk factors on depression. [15,16] In a study on functional neuroimaging, there is a remarkable mood-down-regulation effect due to the increased task in the normal group with a family history of depression than in the normal group without a family history of depression.…”

Chasing Sea Horses in The Depressed Seas: A Ten Years Journey

“…However, the results of those studies are also mixed for hippocampus. For example one study found 6% smaller hippocampal volume in the daughters of depressed patients and another one found smaller hippocampal volume in high-risk twins compared to low-risk twins at p<0.04 levels (18,19). Both of these studies positive finding were at the borderline for significance.…”

Healthy co-twins of patients with affective disorders show reduced risk-related activation of the insula during a monetary gambling task

“…However, the counterintuitive findings are supported by those of a previous imaging study in a larger high-risk twin cohort in which more prominent hippocampal volume reduction was found in the DZ twins than in high-risk MZ twins. 4 It is possible that the observed decrease in insula reactivity to increasing gambling risk and increased neuroticism scores may be best explained by environmental rather than genetic influences. Further, since the rate at which the risk for affective disorders decreases with age in high-risk individuals is not well understood, a higher rate for the MZ twins than the DZ twins may result in a higher ratio of resilient MZ twins than DZ twins in the relatively older MZ cohort.…”

“…Two studies from our group showed lower serotonin (5-HT) transporter binding in the prefrontal cortex 3 and decreased hippocampal volume. 4 We recently observed altered neural response in the hippocampus and orbitofrontal cortex to monetary gains and losses in healthy first-degree relatives of patients with depression.…”

“…Two studies from our group showed lower serotonin (5-HT) transporter binding in the prefrontal cortex 3 and decreased hippocampal volume. 4 We recently observed altered neural response in the hippocampus and orbitofrontal cortex to monetary gains and losses in healthy first-degree relatives of patients with depression. 5 Accordingly, other groups have shown altered frontal and subcortical reward-related neural processes in healthy individuals at familial risk for affective disorders.…”