Lifetime major depression and grey-matter volume

Area of Science:

• Neuroscience
• Psychiatry
• Neuroimaging

Background:

• Major depressive disorder (MDD) is associated with structural brain alterations.
• The influence of age at onset and genetic vulnerability on these alterations is not well understood.
• This study investigates the relationship between lifetime MDD, grey-matter volume, and factors like sex and serotonin transporter-linked promoter region (5-HTTLPR) genotype.

Purpose of the Study:

• To examine if lifetime MDD is associated with specific grey-matter volume alterations.
• To determine if these alterations differ based on sex or 5-HTTLPR genotype.
• To explore variations in brain structure related to age at MDD onset.

Main Methods:

• Structural MRI scans were acquired from 610 community-dwelling participants.
• Grey-matter volume in 16 subregions was quantified using FreeSurfer software.
• MDD was diagnosed using DSM-IV criteria, with analyses adjusted for covariates.

Main Results:

• Lifetime MDD correlated with smaller insula, thalamus, ventral diencephalon, pallidum, and nucleus accumbens, and larger pericalcarine regions.
• Sex-specific differences were observed: smaller caudate nucleus and amygdala in men, larger rostral anterior cingulate cortex in women.
• Age of onset influenced alterations: late-onset MDD associated with larger rostral anterior cingulate cortex, lingual, and pericalcarine regions; early-onset with smaller ventral diencephalon and nucleus accumbens.
• 5-HTTLPR genotype modulated some associations, with thalamus smaller in LL genotype and pericalcarine/lingual volumes higher in SL genotype.

Conclusions:

• MDD is associated with persistent volume reductions in deep nuclei and insula, and enlargements in visual cortex subregions.
• Brain structural alterations in MDD are influenced by age of onset and genetic factors.
• Findings highlight the heterogeneity of brain changes in MDD based on individual characteristics.