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Depression has been found to occur in half of individuals given a diagnosis of Alzheimer’s disease (AD). While evidence suggests depression may be a risk factor for AD, there is also suggestion that depression is a symptom of the disease itself. The exact mechanism behind the association between depression and AD is unknown. However, it is thought the common brain changes associated with childhood trauma, including reduced development of the hippocampus and amygdala and abnormal frontotemporal electrical activity, may play a significant role.

The current study used data from 378 PREVENT participants, from West London, Oxford and Cambridge, to investigate whether midlife adults with a history of childhood trauma had greater risk of both depression, loss of hippocampal volume at midlife and in turn, cognitive performance, and risk of dementia.

It was hypothesised that childhood trauma would be associated with greater clinical depression, lower hippocampal volume and poorer cognitive performance and dementia risk at mid-life. However, while childhood trauma was associated with depression and reduced hippocampal volume, it was not related to current cognitive function or dementia risk.

The findings suggest that the aetiology of depression is different to that of dementia, and the relationship of depression to dementia risk in persons experiencing childhood trauma appears to be neither a risk factor nor a prodromal feature of the disease but that of a comorbidity which may add to brain burden. This study demonstrates that theremay be multiple routes to which depression may appear in individuals with high risk of dementia, and future research in this area should take into account the origins of variety of depression symptomatology.

Key terms and abbreviations: 

Aetiology = The cause of a disease

AD = Alzheimer’s disease

Comorbidity = The simultaneous presence of two or more diseases or conditions in one individual.

By analysing data from our London site’s baseline measures, we discovered that having more chronic physical conditions (multimorbidity) was associated with both depression and anxiety in midlife. However, taking more medications (polypharmacy) was only associated with depression, not anxiety.

These findings highlight an interaction between physical health, medication and mental health at midlife. By following participants further over time and evaluating this interaction we may be able to use this information to inform mental and physical health strategies that may possibly prevent dementia in later life.

Research into Alzheimer’s disease is increasingly focusing on measuring biological markers in the blood, brain and spinal fluid that may reflect early underlying changes in brain health, so called biomarkers. With the discovery and development of biomarkers that may inform an individual’s level of risk for Alzheimer’s disease comes important new ethical considerations. Whilst the accuracy of these biomarkers still need much refinement, weighing up the harms, benefits and rights of risk disclosure to healthy adults will also require much careful consideration before implementing guidelines into care. With the increasing use of such biomarkers in research however, discussions of how best to communicate the value of these results have come to the fore. Central to the decisions of how to manage these discussions has to be the view of patients and research participants.

Focus groups featuring PREVENT participants as well as people living with dementia were held to establish the attitudes and desires of those individuals for who disclosure of such risk information is most pertinent. This publication summarises the opinions voiced in those group discussions around areas such as how best to clearly disclose information and the type of support that should be made available after learning personalised results.

As research into novel treatments for dementia shifts towards earlier intervention and greater understanding of risk factors in a younger population, this generates important new issues of how best to manage risk disclosure. What are the implications of an individual learning their dementia risk? How should this best be communicated? And how might this impact on future life decisions?

To explore these types of questions researchers held focus groups with PREVENT participants to gather opinion on the consequences of these new topics. The discussions centred around the groups expectations on discovering test results that may have implications for risk of future dementia. The three key areas under discussion were; ‘Living At Risk’ – taking proactive steps to reduce risk, ‘Living With Risk’ – maximising cognitive health and accessing healthcare services and ‘Living Beyond Risk’ – planning for later life and adjustment to symptoms.

Advances in research have helped form our current understanding that the earliest brain changes relating to Alzheimer’s disease occur many years before the emergence of any symptoms. This paper highlights the unmet need for measurable markers that can inform us of an individual’s risk profile for later life dementia.

The authors provide a detailed breakdown of the main aims of the PREVENT programme and introduce the methods used to collect the wide range of information from volunteers. They speculate how knowledge gained from PREVENT and other similar studies can shape future prevention strategies to delay or halt the progression of Alzheimer’s disease.