Late-life depression is a common and heterogeneous illness, associated with structural abnormalities in both grey and white matter.

To examine the relationship between age at onset and magnetic resonance imaging (MRI) measures of grey and white matter to establish whether they support particular hypotheses regarding the anatomy and aetiology of network disruption in late-life depression.

We studied 36 participants with late-life depression. Grey matter was examined using T1-weighted MRI and analysed using voxel-based morphometry. The hippocampus was automatically segmented and volume and shape analysis performed. White matter was examined using diffusion tensor imaging and analysed using tract-based spatial statistics.

Later age at onset was significantly associated with reduced fractional anisotropy of widespread tracts, in particular the anterior thalamic radiation and superior longitudinal fasciculus. Earlier age at onset was associated with reduced hippocampal volume normalised to whole brain size bilaterally. However, no significant correlations were detected using hippocampal shape analysis or voxel-based morphometry.

Overall, the results were compatible with the vascular hypothesis, and provided some support for the glucocorticoid cascade hypothesis.

Cognitive impairment precedes the diagnosis of Alzheimer's disease. It is unclear which psychometric measures predict dementia, and what cut-off points should be used. Replicable cognitive measures to provide information about differential diagnosis and prognosis would be clinically useful.

In a prospective cohort study we investigated which measures distinguish between individuals with amnestic mild cognitive impairment (aMCI) that converts to dementia and those whose impairment does not, and which combination of measures best predicts the fate of people with aMCI.

Forty-four participants with aMCI underwent extensive neuropsychological assessment at baseline and annually thereafter for an average of 4 years. Differences in baseline cognitive performance of participants who were converters and non-converters to clinically diagnosed dementia were analysed. Classification accuracy was estimated by sensitivity, specificity, positive and negative predictive values and using logistic regression.

Forty-one percent of participants had progressed to dementia by the end of study, with a mean annual conversion rate of 11%. Most (63%) showed persisting or progressive cognitive impairment, irrespective of diagnosis. The Addenbrooke's Cognitive Examination together with the discrimination index of the Hopkins Verbal Learning Test – Revised (but none of the demographic indices) differentiated the participants who were converters from the non-converters at baseline with 74% accuracy.

Targeted neuropsychological assessment, beyond simple cognitive screening, could be used in clinical practice to provide individuals with aMCI with prognostic information and aid selective early initiation of monitoring and treatment among those who progress towards a clinically diagnosable dementia.

There is current interest in exploring the different subtypes of mild cognitive impairment (MCI), in terms of both their epidemiology and their cognitive profile.

To examine the frequency of MCI subtypes presenting to a memory clinic and to document detailed neuropsychological profiles of patients with the amnestic subtype.

Consecutive tertiary referrals (n = 187) were psychiatrically evaluated; 45 patients met criteria for amnestic mild cognitive impairment (aMCI). A subgroup of 33 patients with aMCI as well as 21 healthy controls took part in a thorough neuropsychological examination.

Of the patients who were examined in greater neuropsychological detail, ten had pure aMCI (none with visual memory impairment only). Fifteen met criteria for non-amnestic MCI. Fifteen had normal neuropsychological profiles. Using more than one test increased sensitivity to detect episodic memory impairment.

Amnestic MCI is an important diagnosis in secondary and tertiary memory clinics. There is scope to improve the efficacy and sensitivity of the clinical assessment of this impairment.

The cognitive impairment of older depressed patients with late- as opposed to early-onset illness may show important differences, in that patients with early onset may suffer predominantly from impaired episodic memory, and those with late onset mainly from reductions of executive function and processing speed.

We searched Medline and EMBASE as well as individual papers' reference lists for relevant publications, recording comparisons in neuropsychological test results between early-onset depression (EOD), late-onset depression (LOD) and healthy volunteers. Effect sizes are presented for cognitive domains, such as executive function, processing speed, episodic memory, semantic memory and mental state examination.

Patients with LOD showed greater reductions in processing speed and executive function than patients with EOD and controls. Both patient groups showed reduced function in all domains, except mental state, compared with controls.

Pronounced executive deficits are typical of the late-onset patients described in published studies, while episodic memory impairment is not specific to early-onset illness. Possible reasons and confounders are discussed.