Expert Comment: Role of stress in dementia investigatedThursday 28 June 2012
Dr Davide Bruno, Lecturer in Psychology at Liverpool Hope, looks at the forthcoming research into whether stress can trigger Alzheimer's disease.
As reported by the BBC, Prof Clive Holmes (University of Southampton) has received funding from Alzheimer's Society to study whether rate of conversion from mild cognitive impairment, a precursor condition of Alzheimer’s disease, to dementia is affected by stress. In this study, individuals will be followed for one and a half year, and their psychological and physical condition will be closely monitored; in particular, biological markers of stress will also be collected at different intervals to determine their stress levels.
The connection between stress and Alzheimer’s disease is certainly an important one – in particular, when considering conditions that involve the presence of chronic stress. For instance, we know that individuals with post-traumatic stress disorder are at greater risk of developing dementia than healthy controls; analogously, major depressive disorder has also been found to be a predictor of Alzheimer’s disease.
A recent study that I co-authored, published in May on the American Journal of Psychiatry (Pomara et al., 2012), for instance, demonstrated that elderly individuals with a diagnosis of major depression – despite not showing any sign of incipient dementia in their behaviour – presented levels of Alzheimer’s disease biomarkers in spinal fluid that were very close to those expected in demented subjects.
In another study (Bruno et al., 2012), published this year in Psychoneuroendocrinology, we found that a combination of genetic variants that are linked to increased risk for Alzheimer’s disease were associated with elevated levels of brain cortisol – a hormone that is released in response to stressful events and that can be neurotoxic in the long term.
All in all, studies such as Professor Holmes’ and the ones described above are fundamental to ensure progress in our understanding of Alzheimer’s, especially when this disease threatens to affect as many as 66 million people worldwide by 2030.