Structural brain correlates of depression and anxiety in middle-aged and older adults: A systematic review

Depression and anxiety are associated with structural brain changes, however, research in middle-aged and older adults is inconclusive regarding the regions implicated and the magnitude or direction of changes. We hypothesised that the impact on brain structure may be greater in this age group. We conducted a systematic review on the associations between brain structure with depression and anxiety separately to determine: i) if there are brain regions consistently implicated in depression and/or anxiety, ii) if these are the same for depression and anxiety or distinct, and iii) the extent to which research has dealt with both disorders together. Brain regions consistently associated with depression include the hippocampus, orbitofrontal cortex, prefrontal cortex, insula and temporal lobe. Relationships were mostly negative, with diminished brain structure being associated with increased depression. We were unable to identify regions consistently implicated in anxiety due to a lack of studies investigating its links with brain structure. This review has highlighted the urgent need for research into brain structure and anxiety in middle-aged and older adults.