New blood test can detect Alzheimer's 3.5 years before diagnosis

Neurogenesis occurs in an important part of the brain called the hippocampus that is involved in learning and memory.

Scientists have developed a blood-based test that could be used to predict the risk of Alzheimer's disease up to 3.5 years before clinical diagnosis.

The research, published in the journal Brain, supports the idea that components in the human blood can modulate the formation of new brain cells, a process termed neurogenesis.

Neurogenesis occurs in an important part of the brain called the hippocampus that is involved in learning and memory.

While Alzheimer's disease affects the formation of new brain cells in the hippocampus during the early stages of the disease, previous studies have only been able to study neurogenesis in its later stages through autopsies.

To understand the early changes, researchers collected blood samples over several years from 56 individuals with Mild Cognitive Impairment (MCI), a condition where someone will begin to experience a worsening of their memory or cognitive ability.

While not everyone experiencing MCI goes on to develop Alzheimer's disease, those with the condition progress to a diagnosis at a much higher rate than the wider population.

Of the 56 participants in the study, 36 went on to receive a diagnosis of Alzheimer's disease.