title: Hippocampal volume changes in healthy subjects at risk of unipolar depression.
abstract: Unipolar 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.
authors.affiliation: Danish Centre for Magnetic Resonance, MR Department, Hvidovre Hospital, University Hospital of Copenhagen, 2650 Hvidovre, Denmark. wimb@drcmr.dk
authors.forename: William F C
authors.initials: WF
authors.lastname: Baaré
authors.forename: Maj
authors.initials: M
authors.lastname: Vinberg
authors.forename: Gitte M
authors.initials: GM
authors.lastname: Knudsen
authors.forename: Olaf B
authors.initials: OB
authors.lastname: Paulson
authors.forename: Annika R
authors.initials: AR
authors.lastname: Langkilde
authors.forename: Terry L
authors.initials: TL
authors.lastname: Jernigan
authors.forename: Lars Vedel
authors.initials: LV
authors.lastname: Kessing
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods; D003866:Depressive Disorder / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006624:Hippocampus / Q000033:anatomy & histology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009929:Organ Size / Q000235:genetics; D012016:Reference Values; D012307:Risk Factors; D014429:Twins, Dizygotic / Q000235:genetics; D014430:Twins, Monozygotic / Q000235:genetics