“…Several distinctions between these groups have been identified, and subjects with early-onset depression are more likely to have a family history of psychiatric illness (Brodaty et al, 2001), while subjects with late-onset depression have greater subcortical ischemic disease (Krishnan et al, 1988;Salloway et al, 1996;Taylor et al, 2004). In addition, late-onset depression has been associated with more pronounced temporal lobe atrophy (Greenwald et al, 1997;Kumar et al, 1998) and hippocampal volume reductions (Steffens et al, 2000;Hickie et al, 2005), with specific genotypes possibly mediating this effect (Taylor et al, 2005). If these previous investigations are interpreted to be signs of different causes or risk factors for depression based on age at onset, greater splenium thinning in late-than early-onset depression might indeed point to more prominent atrophic or neurodegenerative processes in temporal connections, possibly reflecting higher risk for cognitive impairment and dementia conversion in the future (Geda et al, 2006;Salloway et al, 1996;Schweitzer et al, 2002;van Ojen et al, 1995).…”