In a study published today in the Journal of Clinical Psychiatry, based on patients' awareness of their memory problems, researchers have identified a useful method to predict who won't develop Alzheimer's disease. People who were not aware of their memory loss, a condition called anosognosia, were more likely to progress to Alzheimer's disease and those who were aware of memory problems were unlikely to develop dementia.

While memory loss is an early symptom of Alzheimer's disease, its presence does not mean a person will develop dementia. If patients complain of memory problems, but their partner or caregiver isn't overly concerned, it is likely that the memory loss is due to other factors, possibly depression or anxiety. They can be reassured that they are unlikely to develop dementia, and the other causes of memory loss should be addressed.

In other cases, the partner or caregiver is more likely to be distressed while patients don't feel they have any memory problems. In Alzheimer's disease, lack of awareness is linked to more burden on caregivers. Both unawareness of illness (anosognosia) and memory loss (known as a mild cognitive impairment) can be objectively assessed using questionnaires.

The study, believed to be the largest of its kind on illness awareness, had data on 1,062 people aged 55 to 90 from the Alzheimer's Disease Neuroimaging Initiative (ADNI). This included 191 people with Alzheimer's disease, 499 with mild cognitive impairment and 372 as part of the healthy comparison group. The researchers also wanted to identify which parts of the brain were affected by impaired illness awareness.

The team examined the brain's uptake of glucose. Brain cells need glucose to function, but glucose uptake is impaired in Alzheimer's disease. Using PET brain scans, they showed that those with impaired illness awareness also had reduced glucose uptake in specific brain regions, even when accounting for other factors linked to reduced glucose uptake, such as age and degree of memory loss.

The researchers would be tracking older adults with a mild cognitive impairment who are receiving an intervention to prevent Alzheimer's dementia. This ongoing study, the PACt-MD study, combines brain training exercises and brain stimulation, using a mild electrical current to stimulate brain cells and improve learning and memory. Although the study focused on dementia prevention, the team would be looking at whether the intervention improves illness awareness in conjunction with preventing progression to dementia.

In conclusion, the results showed that Anosognosia in the AD is related to brain glucose hypometabolism. Further, anosognosia independently predicts conversion from MCI to the AD. The absence of anosognosia may be clinically useful to identify those patients that are unlikely to convert from MCI to the AD.