Depression and cognition in older adults

Abstract

Recognition that depression is associated with neurocognitive impairment and renewed recent interest in milder forms of cognitive impairment in older people (typified by the concept of mild cognitive impairment) have stimulated researchers to investigate the relationship between depression and cognitive impairment. This review identifies and clarifies recent progress in this rapidly developing research area. Neurocognitive impairment persists in most depressed older people after clinical recovery, and slowed information processing speed and possibly executive dysfunction and vascular risk factors underlie this. Most studies suggest that this neurocognitive impairment in turn leads to increased mild cognitive impairment as well as dementia. White matter disease appears to directly contribute to depression in older people and this worsens over time. Polymorphisms in the serotonin transporter gene may be a key risk factor as well, and depression worsens vascular outcome in peripheral arterial disease. Clinicians should be aware that neurocognitive deficits persist and have an adverse effect on outcome, and that vascular risk factors may contribute to these deficits.